ONGC Placement Paper For Electrical
Q.1 The two windings of a transformer is
(A) conductively linked.
(B) inductively linked.
(C) not linked at all.
(D) electrically linked.
Ans : B
Q.2 A salient pole synchronous motor is running at no load. Its field current is switched off. The motor will
(A) come to stop.
(B) continue to run at synchronous speed.
(C) continue to run at a speed slightly more than the synchronous speed.
(D) continue to run at a speed slightly less than the synchronous speed.
Ans: B
Q.3 The d.c. series motor should always be started with load because
(A) at no load, it will rotate at dangerously high speed.
(B) it will fail to start.
(C) it will not develop high starting torque.
(D) all are true.
Ans: A
Q.4 The frequency of the rotor current in a 3 phase 50 Hz, 4 pole induction motor at full load speed is about
(A) 50 Hz.
(B) 20 Hz.
(C) 2 Hz.
(D) Zero.
Ans: C
Q.5 In a stepper motor the angular displacement
(A) can be precisely controlled.
(B) it cannot be readily interfaced with micro computer based controller.
(C) the angular displacement cannot be precisely controlled.
(D) it cannot be used for positioning of work tables and tools in NC machines.
Ans: A
Q.6 The power factor of a squirrel cage induction motor is
(A) low at light load only.
(B) low at heavy load only.
(C) low at light and heavy load both.
(D) low at rated load only.
Ans: A
Q.7 The generation voltage is usually
(A) between 11 KV and 33 KV.
(B) between 132 KV and 400 KV.
(C) between 400 KV and 700 KV.
(D) None of the above.
Ans: A
Q.8 When a synchronous motor is running at synchronous speed, the damper winding produces
(A) damping torque.
(B) eddy current torque.
(C) torque aiding the developed torque.
(D) no torque.
Ans: D
Q.9 If a transformer primary is energised from a square wave voltage source, its output voltage will be
(A) A square wave.
(B) A sine wave.
(C) A triangular wave.
(D) A pulse wave.
Ans: A
Q.10 In a d.c. series motor the electromagnetic torque developed is proportional to
(A) Ia
(B) (Ia)2
(C) 1/Ia
(D) 1/(Ia)2
Ans: B
Q.11 In a 3 ? phase induction motor running at slip ?s? the mechanical power developed in terms of air gap power
(A) (s-1)Pg
( B) Pg/(1-s)
(C) (1-s)Pg
(D) s.Pg
Ans: C
Q.12 In a 3 ? phase induction motor the maximum torque
(A) is proportional to rotor resistance r2
(B) does not depend on r2
(C) is proportional to sqrt(r2)
(D) is proportional to (r2)2
Ans: B
Q.13 In a d.c. machine, the armature mmf is
(A) stationary w.r.t. armature.
(B) rotating w.r.t. field.
(C) stationary w.r.t. field.
(D) rotating w.r.t. brushes.
Ans: C
Q.14 In a transformer the voltage regulation will be zero when it operates at
(A) unity p.f.
(B) leading p.f.
(C) lagging p.f.
(D) zero p.f. leading.
Ans: B
Q.15 The maximum power in cylindrical and salient pole machines is obtained respectively at load angles of
(A) 900,900
(B) <900,900
(C) 900,>900
(D) 900,<900
Ans: D
Q.16 The primary winding of a 220/6 V, 50 Hz transformer is energised from 110 V, 60 Hz supply. The secondary output voltage will be
(A) 3.6 V.
(B) 2.5 V.
(C) 3.0 V.
(D) 6.0 V.
Ans: C
Q.17 The emf induced in the primary of a transformer
(A) is in phase with the flux.
(B) lags behind the flux by 90 degree.
(C) leads the flux by 90 degree.
(D) is in phase opposition to that of flux.
Ans: C
Q.18 The relative speed between the magnetic fields of stator and rotor under steady state operation is zero for a
(A) dc machine.
(B) 3 phase induction machine.
(C) synchronous machine.
(D) single phase induction machine.
Ans: all options are correct
Q.19 The current from the stator of an alternator is taken out to the external load circuit through
(A) slip rings.
(B) commutator segments.
(C) solid connections.
(D) carbon brushes.
Ans: C
Q.20 A motor which can conveniently be operated at lagging as well as leading power factors is the
(A) squirrel cage induction motor.
(B) wound rotor induction motor.
(C) synchronous motor.
(D) DC shunt motor.
Ans: C
Q.21 A hysteresis motor
(A) is not a self-starting motor.
(B) is a constant speed motor.
(C) needs dc excitation.
(D) can not be run in reverse speed.
Ans: B
Q.22 The most suitable servomotor for low power applications is
(A) a dc series motor.
(B) a dc shunt motor.
(C) an ac two-phase induction motor.
(D) an ac series motor.
Ans: B
Q.23 The size of a conductor used in power cables depends on the
(A) operating voltage.
(B) power factor.
(C) current to be carried.
(D) type of insulation used.
Ans: C
Q.24 Out of the following methods of heating the one which is independent of supply frequency is
(A) electric arc heating
(B) induction heating
(C) electric resistance heating
(D) dielectric heating
Ans: C
Q.25 A two-winding single phase transformer has a voltage regulation of 4.5% at full-load and unity power-factor. At full-load and 0.80 power-factor lagging load the voltage regulation will be
(A) 4.5%.
(B) less than 4.5%.
(C) more than 4.5%.
(D) 4.5% or more than 4.5%.
Ans: C
Q.26 In a dc shunt motor the terminal voltage is halved while the torque is kept constant. The resulting approximate variation in speed ? ?? and armature current ?Ia?? will be
(A) Both ? and Ia are doubled.
(B) ? is constant and Ia is doubled
(C) w is doubled while Ia is halved
(D) w is constant but Ia is halved
Ans: B
Q.27 A balanced three-phase, 50 Hz voltage is applied to a 3 phase, 4 pole, induction motor. When the motor is delivering rated output, the slip is found to be 0.05. The speed of the rotor m.m.f. relative to the rotor structure is
(A) 1500 r.p.m.
(B) 1425 r.p.m.
(C) 25 r.p.m.
(D) 75 r.p.m.
Ans: D
Q.28 An alternator is delivering rated current at rated voltage and 0.8 power-factor lagging case. If it is required to deliver rated current at rated voltage and 0.8 power-factor leading, the required excitation will be
(A) less.
(B) more.
(C) more or less.
(D) the same.
Ans: B
Q.29 A ceiling fan uses
(A) split-phase motor.
(B) capacitor start and capacitor run motor.
(C) universal motor.
(D) capacitor start motor.
Ans: D
Q.30 A stepper motor is
(A) a dc motor.
(B) a single-phase ac motor.
(C) a multi-phase motor.
(D) a two phase motor.
Ans: D
Q.31 The ?sheath? is used in cable to
(A) provide strength to the cable.
(B) provide proper insulation.
(C) prevent the moisture from entering the cable.
(D) avoid chances of rust on strands.
Ans: A
Q.32 The drive motor used in a mixer-grinder is a
(A) dc motor.
(B) induction motor.
(C) synchronous motor.
(D) universal motor.
Ans: D
Q.33 A 1:5 step-up transformer has 120V across the primary and 600 ohms resistance across the secondary. Assuming 100% efficiency, the primary current equals
(A) 0.2 Amp.
(B) 5 Amps.
(C) 10 Amps.
(D) 20 Amps.
Ans: A
Q.34 A dc shunt generator has a speed of 800 rpm when delivering 20 A to the load at the terminal voltage of 220V. If the same machine is run as a motor it takes a line current of 20A from 220V supply. The speed of the machine as a motor will be
(A) 800 rpm.
(B) more than 800 rpm.
(C) less than 800 rpm.
(D) both higher or lower than 800 rpm.
Ans: C
Q.35 A 50 Hz, 3-phase induction motor has a full load speed of 1440 r.p.m. The number of poles of the motor are
(A) 4.
(B) 6.
(C) 12.
(D) 8.
Ans: A
ONGC Aptitude Reasoning Placement Paper
ONGC Solved Sample Paper
ONGC Aptitude/Reasoning/Subject specialisation previous years solved questions with answers
1. If the following numbers are rewritten by interchanging the digits in ten?s place and hundred?s place and then arranging them in the descending order. What will be the second digit of the newly formed fifth number from your right ?
479, 736, 895, 978, 389, 675
(A) 3
(B) 4 (C) 5
(D) 6
Ans : (C)
2. P is 60 m South-East of Q. R is 60 m North-East of Q. Then R is in which direction of P ?
(A) North
(B) North-East
(C) South
(D) South-East
Ans : (A)
Directions?(Q. 3?5) Read the following information for answering the questions that follow?
On a playing ground A, B, C, D and E are standing as described below facing the North.
(i) B is 50 metres to the right of D.
(ii) A is 60 metres to the South of B
(iii) C is 40 metres to the West of D.
(iv) E is 80 metres to the North of A.
3. If a boy walks from C, meets D followed by B, A and then E, how many metres has he walked if he has travelled the straight distance all through ?
(A) 120
(B) 150
(C) 170
(D) 230
Ans : (D)
4. What is the minimum distance (in metre approximately) between C and E?
(A) 53
(B) 78
(C) 92
(D) 120
Ans : (C)
5. Who is to the South-East of the person who is to the left of D ?
(A) A
(B) B
(C) C
(D) E
Ans : (A)
6. A man was walking in the evening just before the sun set. His wife said that, his shadow fell on his right. If the wife was walking in the opposite direction of the man, then which direction the wife was facing ?
(A) North
(B) West
(C) South
(D) East
Ans : (C)
Directions?(Q. 7?11) In each of the following questions choose the set of numbers from the four alternative sets that is similar to the given set.
7. Given set : (4, 9, 18)
(A) (8, 14, 22)
(B) (10, 15, 25)
(C) (6, 12, 23)
(D) (12, 17, 26)
Ans : (D)
8. Given set : (10, 14, 17)
(A) (4, 11, 14)
(B) (9, 12,
(C) (8, 13, 18)
(D) (6, 9, 12)
Ans : (A)
9. Given set : (7, 27, 55)
(A) (21, 35 , 52)
(B) (18, 42 , 65)
(C) (16, 40 , 72)
(D) (13, 30 , 58)
Ans : (C)
10. Given set : (39, 28, 19)
(A) (84, 67 , 52)
(B) (52, 25 , 17)
(C) (70, 49 , 36)
(D) (65, 45 , 21)
Ans : (A)
11. Given set : (246, 257, 358)
(A) (233, 343, 345)
(B) (273, 365, 367)
(C) (143, 226, 237)
(D) (145, 235, 325)
Ans : (A)
Directions?(Q. 12?16) Each question contains six or seven statements followed by four sets of combinations of three. Choose the set in which the statements are logically related.
12.
(1) All books are having pages.
(2) All kings are having pages.
(3) All kings are books.
(B) 4, 2, 6
(C) 1, 5, 3
(D) 2, 4, 5
Ans : (B)
Directions?(Q. 17?21) Each of the questions below consists of a question and two statements numbered (I) and (II). You have to decide whether the data provided in the statements are sufficient to answer the question. Give answers?
(A) If the data in statement (I) alone are sufficient to answer the question, while the data in statement (II) alone are not sufficient to answer the question;
(B) If the data in statement (II) alone are sufficient to answer the question, while the data in statement (I) alone are not sufficient to answer the questions;
(C) If the data even in both statements (I) and (II) together are not sufficient to answer the question;
(D) If the data in both statement (I) and (II) together are necessary to answer the question.
17. In which direction is Mahatmaji?s statue facing ?
I. The statue is towards the northern end of the city.
II. The statue?s shadow falls towards East at 5 O?clock in the evening.
Ans : (C)
18. What is the total number of pupils in the final year class ?
I. The number of boys in the final year class is twice as much as the number of girls in that class.
II. The sum of the ages of all the pupils in the class is 399 years and their average age is 19 years.
Ans : (B)
19. Who is the tallest among A, B, C and D ?
I. A is taller than C.
II. B is taller than C and D.
Ans : (C)
20. How many Sundays are there in a particular month of a particular year?
I. The month begins on Monday.
II. The month ends on Wednesday.
Ans : (D)
21. What is the total number of pages in this book ?
I. I counted 132 pages from the beginning of this book.
II. My wife counted 138 pages starting from the end of the same book.
Ans : (C)
Directions?(Q. 22?26) In each of the questions given below, there is a statement followed by three assumptions numbered I, II and III. An assumption is something supposed or taken for granted. You have to consider the statement and assumptions and then decide, which of the assumption(s) is/are implicit in the statement.
22. Statement : During pre-harvest kharif seasons, the government has decided to release vast quantity of foodgrains from FCI.
Assumptions :I. There may be a shortage of foodgrains in the market during this season.
II. The kharif crop may be able to replenish the stock of FCI.
III. There may be a demand from the farmers to procure kharif crop immediately after harvest.
(A) None is implicit
(B) Only I and II are implicit (C) Only II and III are implicit (D) All are implicit
Ans : (D)
23. Statement : To improve the employment situation in India, there is a need to recast the present educational system towards implementation of scientific discoveries in daily life.
Assumptions :I. The students after completing such education may be able
to earn their livelihood.
II. This may bring meaning of education in the minds of the youth.
III. The state may earn more revenue as more and more people will engage themselves in self employment.
(A) Only I and II are implicit
(B) Only III is implicit
(C) Only I and III are implicit
(D) None is implicit
Ans : (A)
24. Statement : To increase profit, the oil exporting countries decided to reduce the production of crude by 5 million barrels per day. Assumptions :I. The price of crude may increase due to less production. II. The demand of crude may remain same in future.
III. Other countries may continue buying crude from these countries. (A) All are implicit
(B) Only II and III are implicit (C) Only I and II are implicit (D) None is implicit
Ans : (C)
25. Statement : ?We do not want you to see our product on newspaper, visit our shop to get a full view.? ? an advertisement.
Assumptions :I. People generally decide to purchase any product after seeing the name in the advertisement.
II. Uncommon appeal may attract the customers. III. People may come to see the product.
(A) All are implicit
(B) None is implicit
(C) Only II and III are implicit
(D) Only I and II are implicit
Ans : (A)
26. Statement : The Reserve Bank of India has directed the banks to refuse fresh loans to major defaulters.
Assumptions :I. The banks may still give loans to the defaulters.
II. The defaulters may repay the earlier loan to get fresh loan.
III. The banks may recover the bad loans through such harsh measures.
(A) All are implicit
(B) None is implicit
(C) Both II and III are implicit
(D) Both I and II are implicit
Ans : (C)
Directions?(Q. 27?31) In questions given below, statements 1 and 2 are followed by conclusions I and II. Taking the statements to be right although they may seem at variance with commonly accepted facts, mark your answers as under?
(A) If only conclusion I follows.
(B) If only conclusion II follows.
(C) If both I and II follows.
(D) Neither I nor II follows.
27. Statements :
1. All hands are machines.
2. All machines are wheels.
Conclusions :I. All wheels are hands.
II. All hands are wheels.
Ans : (B)
28. Statements :
1. Some buds are leaves.
2. Some leaves are red. Conclusions :
I. Some buds are red.
II. Some leaves are not buds.
Ans : (B)
29. Statements :
1. Some stones are shells.
2. All shells are pearls.
Conclusions :
I. Some stones are pearls.
II. All pearls are shells.
Ans : (A)
30. Statements :
1. Brown is red and blue is green.
2. Green is pink and yellow is red. Conclusions :
I. Yellow is brown.
II. Pink is blue.
Ans : (C)
Placement Paper
ONGC Chemical Engineering Technical Questions,ONGC Grduate Trainees previous years solved question papers
Most of the questions are from previous GATE papers, Specially numerical questions.
1. Sherwood Number Is the ratio of? Convective Mass transfer coefficient to Diffusive Mass transfer coefficient. ( Sh = KL/D)
2. Catalyst in the manufacture of HNO3? Pt-Rh catalyst
3. Process used to convert Black liquor to white liquor? ANS:
4. What is Capitalised cost?
5. Which type of agitator will be used for viscous liquids?
6. Cavitation in pumps can be avoided by? Maintaining high vapour pressure.
7. What is Bode Criteria? A feedback control system is unstable if amplitude ratio of corresponding open loop transfer function is larger than 1 at the cross over frequency.
8. After absorption of Ammonia in water how it can be recovered?
9. According to Collision theory How “T” and “K” are related? K proportional to T^1/2
10. Which law gives about the generation of EMF?
11. What is the Change in entropy in mixing two components?
12. Glass etching can be done by using?
13. What is Plancks law, Kirchoffs law and Stefan boltzman law ?
14. What is the reason for not using saturated steam in evaporator?
15. Order of reaction for which the size of MFR is bigger than PFR?
16. How optimum reflux ratio can be chosen?
17. For gaseous reactions which reactor will give best result?
18. Penetration theory in Mass transfer?
19. What is the maximum allowable pressure drop on tube side in shell and tube heat exchangers?
20. For exothermic reactions as the temperature decreased ,how rate of reaction changes?
21. Corner Frequency corresponds to angle?
22. During Condensation which property does not change?
23. If Pr>1, then heat transfer confined to? Viscous sub layer
24. Minimum offset and oscillation occur with which type of controller?
25. Head developed by a pump depends on?
26. In cooling towers efficiency can be increased by ?
27. Ultrafine grinding uses which mechanism?
28. Composition of synthesis gas?
29. Aniline point of diesel shows?
30. Three unequal sized mixed flow reactors of volume 5L, 10L, 15L are arranged in which order for reactions of order n>0?
31. For natural convection Nusselt number is the function of?
32. Which mechanism is used in Fluid energy mill?
33. Film coefficient of heat transfer defined as?
34. Petroleum coke is made by residue by which process?
35. Chemical used in the test of COD?
36. Product of reaction between acetylene and chlorine?
37. For first order reactions, if thiele modulus is 10, then effectiveness factor is? 0.1
38. Graph between 1/C0 vs t is straight for reactions of order? 2
39. Which type of arrangement used for cold and viscous feed? Backward feed
40. Superheated steam is not used in evaporator dur to? Low heat transfer coefficient
41. Byproduct in the production of phosphoric acid ? Gypsum
42. The equivalent diameter for flow through rectangular duct of width B and Height H is? 2(BH)/(B+H)
43. What is dead time in process control?
44. For gas phase reaction 2A->B, feed consists of 80 mole% A and 20 mol% inerts. If the conversion of A at the reactor exit is 50%, then CA/CA0 at the reactor outlet is?
45. Numerical on Pitot tube .
46. For exothermic reactions under adiabatic condition conversion goes through? Reaches maximum
47. View factor for concentric Spheres of radius R2 for smaller and R1 for larger sphere is?
48. Chemical Used in the test of COD?
49. LMTD correction factor?
50. H2S and S can be removed by using?
51. Newtons law of motion , analogous to what law in mass transfer?
ONGC General Awareness Questions
1. Untouchability speech is given by ?
2. CAG administration and rules are under Article?
3. Who inspired from R Tagores Geetanjali?
4. Badami caves built by? Chalukyas
5. Supreme court writs under article?
6. Election dispute in the election of vice president resolved by?
7. If both the houses are absent then the president ordinance valid for how many days?
8. Order of importance among, chief justice of india, election commissioner,cabinet minister, cabinet secretary?
9. Oxygenated blood is in which side of Heart?
10. Good Cholesterol? HDL
11. Blood test after fasting gives?
12. Flag bearer in the ending ceremony of Olympics?
13. Last NAM summit held in?
14. Match the following
Orissa- Paradip
Maharashtra- Jawahar lal Nehru Port
Gujarat- Kandla
15. Match the following, about projects and rivers?
16. Shakespears novel in which a murder by poison ?
17. Blue vitriol?
18. Which city lies in two continents?
19. Seven sisters of north east?
20. What is sierra leone?
21. Largest uranium reserves in the World?
22. Places with same rain fall are connected by? isohytes
23. Who had written stories on partition of India? R.K.Narayan
24. Who is the emerging player by ICC?
25. Which is not an epic?
26. Composition of solder?
27. Food poison caused by?
28. Ascending order of speed among Floppy , RAM, Cache, Harddisk?
29. Red blood cells are abundant in?
Wishing All the best and good luck.
Sathish
ONGC General-Awareness
Oil and Natural Gas Corporation is the government undertaking that works under the Ministry of Petroleum and Gas.We have given the ONGC Graduate Trainee sample papers of General Awareness below.Read the ONGC graduate trainee previous year question papers to analyze the exam pattern and important topics in the subject for the better preparation to get good score in the examination.
ONGC Sample Paper
General Awareness
1.Women20-20 world Championship was Won By
(A)Australia
(B)England
(C)Pakistan
(D) India
2. Who is the Chairperson of Identification Authority of India (UIA)?
(A) Dr. M. S. Swaminathan
(B) Nandan Nilekani
(C) B. Shreedharan
(D) M. N. Buch
3. Who won the 2009 Wimbledon ?
(A) Pete Samptas
(B) Rafael Nadal
(C) Roger Federer
(d) John McEnroe
4. Which country has the largest Rail Network in the World?
(A)India
(B) U. K.
(C)China
(D) U.S.A.
5. Who is the Union Law Minister of India?
(A) Sharad Pawar
(B) Kapil Sibbal
(C) Verrappa Moily
(D) Hansraj Bharadwaj
6. The Birthday of Late Sarvepalli Radhakrishnan, ?President of India?, is celebrated as?
(A)Lawyer?s Day
(B)Teacher?s Day
(C)Children?s Day
(D)Father?s Day
7. Tirupati is in?
(A) Andhra Pradesh
(B) Karnatalca
(C) Tamil Nadu
(D) MP
8. Kanha National Park is situated in which State ?
(A) Andhra Pradesh
(B) Karnatalca
(C) Tamil Nadu
(D) MP
9. River Narmada originates from?
(A) Bhedaghat
(B) Amarkantak
(C) Dindori
(D) Allahabad
10. Gandhiji started Dandi March in 1930
(A) Against atrocities committed on Harijarts
(B) Against imposition of Salt Tax
(C) Against the commencement of Communal Riot
(D) Against prohibition on Indian?s participating in elections
11. Who is the author of ?My Experiments with Truth??
(A)Nehru
(B) Tagore
(C) Gandhi
(D) Jinnah
12. NASA refers to
(A) National Aeronautics and Space Administration
(B) North Atlantic Space Agency
(C) North Airbase and Space Agency
(D) None of the above
13. I.S.O. 9000 is a?
(A) Quality Standard Mark
(B) Space Project
(C) Trade Technique
(d) None of these
14. Who among the following made a film on Mahatma Gandhi?
(A) Aparna Sen
(B) ShyamBenegal
(C) James Ivory
(d) Richard Attenborough
15. ?Law Day? is observed on
(A) 26th January
(B) 15th August
(C) 26th May
(d) 26th November
16. Which is the longest sea bridge in the country?
(A) Vidyasagar Sew, Kolkata
(B) Bandra-Worli Sea Link,Mumbai
(C) Bhakra-Nangal Project
(D) None of these
17. Dr. Rajendra Pachauri is a/an?
(A) Banker
(B) Industrialist
(C) Environmentalist
(D) Scientist
18. Who is the author of ?Discovery of India??
(A) Jawaharlal Nehru
(B) Mahatma Gandhi
(C) Sarojini Naidu
(D) Indira Gandhi
19. D.N.A. refers to?
(A)Di-oxyribo Nucleic Acid
(B)Di-oxide Nucleic Acid
(C)Different Nucleic Acid
(D) None of these.
20. S.M.S. is?
(A)Short Messaging Sequence
(B)Short Messaging Service
(C)Short Manageable Service
(D)Short and Medium Service
21. Padma Bhushan Award is?
(A) Gallantry Award
(B) Bravery Award
(C) Civilian Award
(d), Literary Award
22. Which city is known as the ?City of Joy??
(A)Delhi
(B) Mumbai
(C)Kolkata
(D) Chennai
23. Who won the ASHES Cricket Test Series held in year 2009?
(A)Australia
(B)England
(C)Pakistan
(D) None of these
24. Who appoints a Judge of a High Court?
(A) Governor
(B) Chief Minister
(C) President of i
(D) Chief Justice of India
25. Which of these animals is not shown in the National Emblem of India?
(A)Lion
(B) Horse
(C)Bull
(D) Elephant
26. Which is the Mother State of Chhattisgarh?
(A) Bihar
(B) Uttar Pradesh
(C) Uttarakhand
(D) Madhya Pradesh
27. Who won the men?s 100 m. final race at the recently held 2009 IAAF Athletics World Championship in Berlin?
(A) Tyson Gay of America
(B) Usain Bolt of Jamaica
(C) Asafa Powell of Jamaica
(D) Yang Yon Eun of South Korea
28. The Finance Minister has pro posed replacement of the Income Tax Act by?
(A) The Finance Act, 2008
(B) The Direct Tax Act
(C) The Indian Taxation Code
(D) The Direct Taxes Code
29. The Earth rotates around an axis pointing towards
(A) the moon
(B) the pole star
(C) the sun
(D) Venus
30. Which one of the following aptly describes the generalised shape of the continents?
(A)Circular
(B) Hexagonal
(C)Rectangular
(D) Triangular
31.An Air India plane recently crashed at ??.. Airport
(A) Mumbai
(B) Kolkata
(C) Mangalore
(D) Srinagar
32.Vikas Krishnan was in news Recently. He is a ?
(A) Boxer
(B) Writer
(C)Music Director
(D) Head of VIKAS NGO
33. During 1994-2007 grean house gas Emissions in India Fell By
(A) 25 percent
(B) 30 percent
(C) 35 percent
(D) 40 percent
34.First European Country to Ban Burqua is ?
(A) Belgium
(B) France
(C) UK
(D) Germany
General – other
This is ONGC paper for GS :-
this paper asked 40 questions which were quite difficult because some peculiar (other than usual)types were there-
Subjective GS questions:-
1- Unity in Diversity
2- Impact of Globalization on Rural Economy.
Objective:
1) First aerospace SEZ applied in which place?
ans) Hattaragi, dist. Belgaum, Karnatka.
2) In Africa which river passes twice TRopic of Capricon?
ans) river :Limppopo
3)who started mansabdari system?
ans) Akbar
4)who is chief of IAEA?
ans) Yukia Amano
5)who was the president of INC during Surat Split in 1907?
ans) Ras Bihari Bose
6)President of India submits his resignation to whom ?
ans) Vice-President
7)which company hired CISF securty first?
a)infosis b)TCS c)Wipro d)TechMahindra
8)who fist acted for untouchables?
ans)Jyotibha Phule
9)Who wrote the book “Neel Daarpan”?
ans) Dinbandhu Mitra
10) Tatipudi Reservoir in which state?
ans) Andhra Pradesh
11) National Environmental Engineering Research Institute situtated where?
ans) Nagpur
12) INS Arihant nuclear powered submarine generates power?
ans) 85MW
13) highest peak of Satpura mountains?
ans)Dhoopgarh peak
14) Demand of Fundamental Rights are raised in which sesssion of INC?
ans) Karachi Session
15) Red Blood Corpuscles are commenly known as?
ans) Erythrocytes
16) which cabohydrate is sweetest?
a) glucose b)maltose c)fructose d)lactose
ans) fructose
17)venue of 2010 football world cup?
ans) South Africa
18)The min age qualification for supreme court Judge?
ans) No age limit, 10 years experience in highcourt as a judge
ONGC electronics and electrical questions with answers ONGC A.C. Fundamentals, Circuits and Circuit Theory – Electrical engineering multiple choice questions and answers for competitive exams,ONGC Electrical Engineering Questions and Answers
,
1. A sine wave has a frequency of 50 Hz. Its angular frequency is _______ radian/second.
(a) 100 n
(b) 50 jt
(c) 25 jt
(d) 5 n
Ans: a
2. The reactance offered by a capacitor to alternating current of frequency 50 Hz is 20 Q. If frequency is increased to 100 Hz, reactance becomes_____ohms.
(a) 2.5
(b) 5
(c) 10
(d) 15
Ans: c
3. The period of a wave is
(a) the same as frequency
(6) time required to complete one cycle
(c) expressed in amperes
(d) none of the above
Ans: b
4. The form factor is the ratio of
(a) peak value to r.m.s. value
(6) r.m.s. value to average value
(c) average value to r.m.s. value
(d) none of the above
Ans: b
5. The period of a sine wave is _____ seconds.
Its frequency is
(a) 20 Hz
(b) 30 Hz
(c) 40 Hz
(d) 50 Hz
Ans: d
6. A heater is rated as 230 V, 10 kW, A.C. The value 230 V refers to
(a) average voltage
(b) r.m.s. voltage
(c) peak voltage
(d) none of the above
Ans: b
7. If two sinusoids of the same frequency but of different amplitudes and phase angles are subtracted, the resultant is
(a) a sinusoid of the same frequency
(b) a sinusoid of half the original frequency
(c) a sinusoid of double the frequency
(d) not a sinusoid
Ans: a
8. The peak value of a sine wave is 200 V. Its average value is
(a) 127.4 V
(b) 141.4 V
(c) 282.8 V
(d)200V
Ans: a
9. If two sine waves of the same frequency have a phase difference of JT radians, then
(a) both will reach their minimum values at the same instant
(b) both will reach their maximum values at the same instant
(c) when one wave reaches its maximum value, the other will reach its minimum value
(d) none of the above
Ans: c
10. The voltage of domestic supply is 220V. This figure represents
(a) mean value
(b) r.m.s. value
(c) peak value
(d) average value
Ans: a
11. Two waves of the same frequency have opposite phase when the phase angle between them is
(a) 360°
(b) 180°
(c) 90°
(d) 0°
Ans: b
12. The power consumed in a circuit element will be least when the phase difference between the current and
voltage is
(a) 180″
(b) 90°
(c) 60°
(d) 0°
Ans: b
13. The r.m.s. value and mean value is the same in the case of
(a) triangular wave
(6) sine wave
(c) square wave
(d) half wave rectified sine wave
Ans: c
14. For the same peak value which of the following wave will ‘have the highest r.m.s. value ?
(a) square wave
(b) half wave rectified sine wave
(c) triangular wave
(d) sine wave
Ans: a
15. For the same peak value, which of the following wave has the least mean value ?
(a) half wave rectified sine wave
(b) triangular wave
(c) sine wave
(d) square wave
Ans: a
16. For a sine wave with peak value Imax the r.m.s. value is
(a) 0.5 Imax
(b) 0.707
(c) 0.9
(d) 1.414 Lmax
Ans: b
17. Form Factor is the ratio of
(a) average value/r.m.s. value
(b) average value/peak value
(e) r.m.s. value/average value
(d) r.m.s. value/peak value
Ans: c
18. Form factor for a sine wave is
(a) 1.414
(b) 0.707
(c) 1.11
(d) 0.637
Ans: c
19. For a sine wave with peak value Emax______8.30. the average value is
(a) 0.636 Emax
(b) 0.707 Emax
(c) 0.434 EWc
(d) lAUEmax
Ans: a
20. For a frequency of 200 Hz, the time period will be
(a) 0.05 s
(b) 0.005 s
(c) 0.0005 s
(d) 0.5 s
Ans: b
21. The phase difference between voltage and current wave through a circuit element is given as 30°. The essential condition is that
(a) both waves must have same frequency
(b) both waves must have identical peak values
(c) both waves must have zero value at the same time
(d) none of the above
Ans: a
22. The r.m.s. value of a sinusoidal A.C. current is equal to its value at an angle of______degrees.
(a) 90
(b) 60
(c) 45
(d) 30
Ans: c
23. Capacitive reactance is more when
(a) capacitance is less and frequency of supply is less
(b) capacitance is less and frequency of supply is more
(c) capacitance is more and frequency of supply is less
(d) capacitance is more and frequency of supply is more
Ans: a
24. In a series resonant circuit, the impedance of the circuit is
(a) minimum
(b) maximum
(c) zero
(d) none of the above
Ans: a
25. Power factor of an electrical circuit is equal to
(a) R/Z
(b) cosine of phase angle difference between current and voltage
(c) kW/kVA
(d) ratio of useful current to total current Iw/I
(e) all above
Ans: e
26. The best place to install a capacitor is
(a) very near to inductive load
(b) across the terminals of the inductive load
(c) far away from the inductive load
(d) any where
Ans: b
27. Poor power factor
(a) reduces load handling capability of electrical system
(b) results in more power losses in the electrical system
(c) overloads alternators, transformers and distribution lines
(d) results in more voltage drop in the line
(e) results in all above
Ans: e
28. Capacitors for power factor correction are rated in
(a) kW
(b) kVA
(c) kV
(d) kVAR
Ans: d
29. In series resonant circuit, increasing inductance to its twice value and reducing capacitance to its half value
(a) will change the maximum value of current at resonance
(6) will change the resonance frequency
(c) will change the impedance at resonance frequency
(d) will increase the selectivity of the circuit
Ans: d
30. Pure inductive circuit
(a) consumes some power on average
(b) does not take power at all from a line
(c) takes power from the line during some part of the cycle and then returns back to it during other part of the cycle
(d) none of the above
Ans: c
31. Inductance affects the direct current flow
(a) only at the time of turning off
(b) only at the time of turning on
(c) at the time of turning on and off
(d) at all the time of operation
Ans: c
32. Inductance of a coil Varies
(a) directly as the cross-sectional area of magnetic core
(b) directly as square of number of turns
(c) directly as the permeability of the core
(d) inversely as the length of the iron path
(e) as (a) to (d)
Ans: e
33. All the rules and laws of D.C. circuit also apply to A.C. circuit containing
(a) capacitance only
(b) inductance only
(c) resistance only
(d) all above
Ans: c
34. Time constant of an inductive circuit
(a) increases with increase of inductance and decrease of resistance
(b) increases with the increase of inductance and the increase of resistance
(c) increases with decrease of inductance and decrease of resistance
(d) increases with decrease of inductance and increase of resistance
Ans: a
35. Power factor of an inductive circuit is usually improved by connecting capacitor to it in
(a) parallel
(b) series
(c) either (a) or (b)
(d) none of the above
Ans: a
36. In a highly capacitive circuit the
(a) apparent power is equal to the actual power
(b) reactive power is more than the apparent power
(c) reactive power is more than the actual powetf
(d) actual power is more than its reactive power
Ans: c
37. Power factor of the following circuit will be zero
(a) resistance
(b) inductance
(c) capacitance
(d) both (b) and (c)
Ans: d
38. Power factor of the following circuit will be unity
(a) inductance
(b) capacitance
(c) resistance
(d) both (a) and (b)
Ans: c
39. Power factor of the system is kept high
(a) to reduce line losses
(b) to maximise the utilization of the capacities of generators, lines and transformers
(c) to reduce voltage regulation of the line
(d) due to all above reasons
Ans: d
40. The time constant of the capacitance circuit is defined as the time during which voltage
(a) falls to 36.8% of its final steady value
(b) rises to 38.6% of its final steady value
(c) rises to 63.2% of its final steady value
(d) none of the above
Ans: c
41. In a loss-free R-L-C circuit the transient current is
(a) oscillating
(b) square wave
(c) sinusoidal
(d) non-oscillating
Ans: c
42. The r.m.s. value of alternating current is given by steady (D.C.) current which when flowing through a given circuit for a given time produces
(a) the more heat than produced by A.C. when flowing through the same circuit
(b) the same heat as produced by A.C. when flowing through the same circuit
(c) the less heat than produced by A.C. flowing through the same circuit
(d) none of the above
Ans: b
43. The square waveform of current has following relation between r.m.s. value and average value.
(a) r.m.s. value is equal to average value
(b) r.m.s. value of current is greater than average value
(c) r.m.s. value of current is less than average value
(d) none of the above
Ans: a
44. The double energy transient occur in the
(a) purely inductive circuit
(b) R-L circuit
(c) R-C circuit
(d) R-L-C circuit
Ans: d
45. The transient currents are associated with the
(a) changes in the stored energy in the inductors and capacitors
(b) impedance of the circuit
(c) applied voltage to the circuit
(d) resistance of the circuit
Ans: a
46. The power factor at resonance in R-L- C parallel circuit is
(a) zero
(b) 0.08 lagging
(c) 0.8 leading
(d) unity
Ans: d
47. In the case of an unsymmetrical alternating current the average value must always be taken over
(a) unsymmetrical part of the wave form
(b) the quarter cycle
(c) the half cycle
(d) the whole cycle
Ans: d
48. In a pure resistive circuit
(a) current lags behind the voltage by 90°
(b) current leads the voltage by 90°
(c) current can lead or lag the voltage by 90°
(d) current is in phase with the voltage
Ans: d
49. In a pure inductive circuit
(a) the current is in phase with the voltage
(b) the current lags behind the voltage by 90°
(c) the current leads the voltage by 90°
(d) the current can lead or lag by 90°
Ans: b
50. In a circuit containing R, L and C, power loss can take place in
(a) C only
(b) L only
(c) R only
(d) all above
Ans: c
51. Inductance of coil
(a) is unaffected by the supply frequency
(b) decreases with the increase in supply frequency
(c) increases with the increase in supply frequency
(d) becomes zero with the increase in supply frequency
Ans: c
52. In any A.C. circuit always
(a) apparent power is more than actual power
(b) reactive power is more than apparent power
(c) actual power is more than reactive power
(d) reactive power is more than actual power
Ans: a
53. Which of the following circuit component opposes the change in the circuit voltage ?
(a) Inductance
(b) Capacitance
(c) Conductance
(d) Resistance
Ans:
54. In a purely inductive circuit
(a) actual power is zero
(b) reactive power is zero
(c) apparent power is zero
(d) none of above is zero
Ans: a
55. Power factor of electric bulb is
(a) zero
(b) lagging
(c) leading
(d) unity
Ans: d
56. Pure inductive circuit takes power from the A.C. line when
(a) applied voltage decreases but cur¬rent increases
(b) applied voltage increases but cur¬rent decreases
(c) both applied voltage and current increase
(d) both applied voltage and current decrease
Ans: a
57. Time constant of a circuit is the time in seconds taken after the application of voltage to each
(a) 25% of maximum value
(b) 50% of maximum value
(c) 63% of maximum value
(d) 90% of the maximum value
Ans: c
58. Time constant of an inductive circuit
(a) increases with increase of inductance and decrease of resistance
(b) increases with the increase of inductance and the increase of resistance
(c) increases with the decrease of inductance and decrease of resistance
(d) increases with decrease of inductance and increase of resistance
Ans: a
59. Time constant of a capacitive circuit
(a) increases with the decrease of capacitance and decrease of resistance
(b) increases with the decrease of capacitance and increase of resis¬tance
(c) increases with the increase of capacitance and decrease of resis¬tance
(d) increase with increase of capacitance and increase of resis¬tance
Ans: d
60. Magnitude of current at resonance in R-L-C circuit
(a) depends upon the magnitude of R
(b) depends upon the magnitude of L
(c) depends upon the magnitude of C
(d) depends upon the magnitude of R, LandC
Ans: a
61. In a R-L-C circuit
(a) power is consumed in resistance and is equal to I R
(b) exchange of power takes place between inductor and supply line
(c) exchange of power takes place between capacitor and supply line
(d) exchange of power does not take place between resistance and the supply line
(e) all above are correct
Ans: e
62. In R-L-C series resonant circuit magnitude of resonance frequency can be changed by changing the value of
(a) R only
(b) L only
(c) C only
(d) L or C
(e) R,L or C
Ans: d
63. In a series L-C circuit at the resonant frequency the
(a) current is maximum
(b) current is minimum
(c) impedance is maximum
(d) voltage across C is minimum
Ans: a
64. The time constant of a series R-C circuit is given by
(a) R/C
(b) RC2
(c) RC
(d) R2C
Ans: c
65. If resistance is 20 Q. and inductance is 27 in a R-L series circuit, then time constant of this circuit will be
(a) 0.001 s
(b) 0.1 s
(c) 10 s
(d) 100 s
Ans: b
66. Which of the following coil will have large resonant frequency ?
(a) A coil with large resistance
(b) A coil with low resistance
(c) A coil with large distributed capacitance
(d) A coil with low distributed capacitance
Ans: c
67. If a sinusoidal wave has frequency of 50 Hz with 30 A r.m.s. current which of the following equation represents this wave ?
(a) 42.42 sin 3141
(b) 60 sin 25 t
(c) 30 sin 50 t
(d) 84.84 sin 25 t
Ans: a
68. The safest value of current the human body can carry for more than 3 second is
(a) 4 mA
(b) 9 mA
(c) 15 mA
(d) 25 mA
Ans: b
69. A pure inductance connected across 250 V, 50 Hz supply consumes 100 W.
This consumption can be attributed to
(a) the big size of the inductor
(b) the reactance of the inductor
(c) the current flowing in the inductor
(d) the statement given is false
Ans: d
70. The input of an A.C. circuit having power factor of 0.8 lagging is 40 kVA
The power drawn by the circuit is
(a) 12 kW
(b) 22 kW
(c) 32 kW
(d) 64 kW
Ans: c
71. The effective resistance of an iron-cored choke working on ordinary supply frequency is more than its true resistance because of
(a) iron loss in core
(b) skin effect
(c) increase in temperature
(d) capacitive effect between adjacent coil turns
Ans: a
72. In an AC. circuit, a low value of kVAR compared with kW indicates
(a) low efficiency
(b) high power factor
(c) unity power factor
(d) maximum load current
Ans: b
73. In AC. circuits, laminated iron is invariably used in order to
(a) reduce eddy current loss
(b) increase heat radiation
(c) make assembly cheap and easier
(d) reduce circuit permeability
Ans: a
74. The ratio of active power to apparent power is known as factor.
(a) demand
(b) load
(c) power
(d) form
Ans: c
75. All definitions of power factor of a series R-L-C circuit are correct except
(a) ratio of net reactance and impedance
(b) ratio of kW and kVA
(c) ratio of J and Z
(d) ratio of W and VA
Ans: a
76. The apparent power drawn by an A.C. circuit is 10 kVA and active power is 8 kW. The reactive power in the circuit is
(a) 4 kVAR
(b) 6 kVAR
(c) 8 kVAR
(d) 16 kVAR
Ans: b
77. What will be the phase angle between two alternating waves of equal frequency, when one wave attains maximum value the other is at zero value ?
(a) 0°
(b) 45°
(c) 90°
(d) 180°
Ans: c
78. The purpose of a parallel circuit resonance is to magnify
(a) current
(b) voltage
(c) power
(d) frequency
Ans: b
79. In an A.C. circuit power is dissipated in
(a) resistance only
(b) inductance only
(c) capacitance only
(d) none of the above
Ans: a
80. In a parallel R-C circuit, the current always______the applied voltage
(a) lags
(b) leads
(c) remains in phase with
(d) none of the above
Ans: b
81. At very low frequencies a series R-C circuit behaves as almost purely
(a) resistive
(b) inductive
(c) capacitive
(d) none of the above
Ans: c
82. Skin effect occurs when a conductor carries current at _____ frequencies.
(a) very low
(b) low
(c) medium
(d) high
Ans: d
83. At ______ frequencies the parallel R-L circuit behaves as purely resistive.
(a) low
(b) very low
(c) high
(d) very high
Ans: d
84. In a sine wave the slope is constant
(a) between 0° and 90°
(b) between 90° and 180°
(c) between 180° and 270°
(d) no where
Ans: d
85. The power is measured in terms of decibles in case of
(a) electronic equipment
(b) transformers
(c) current transformers
(d) auto transformers
Ans: a
86. Capacitive susceptance is a measure of
(a) reactive power in a circuit
(b) the extent of neutralisation of reactive power in a circuit
(c) a purely capacitive circuit’s ability to pass current
(d) a purely capacitive circuit’s ability to resist the flow of current
Ans: c
87. Which of the following statements pertains to resistors only ?
(a) can dissipate considerable amount of power
(6) can act as energy storage devices
(c) connecting them in parallel in¬creases the total value
(d) oppose sudden changes in voltage
Ans: a
88. Which of the following refers to a parallel circuit ?
(a) The current through each element is same
(b) The voltage across element is in proportion to it’s resistance value
(c) The equivalent resistance is greater than any one of the resistors
(d) The current through any one element is less than the source current
Ans: d
89. Aphasoris
(a) a line which represents the mag¬nitude and phase of an alternating quantity
(b) a line representing the magnitude and direction of an alternating quantity
(c) a coloured tag or band for distinction between different phases of a 3-phase supply
(d) an instrument used for measuring phases of an unbalanced 3-phase load
Ans: a
89. A parallel AC. circuit in resonance will
(a) have a high voltage developed across each inductive and capacitive section
(b) have a high impedance
(c) act like a resistor of low value
(d) have current in each section equal to the line current
Ans: b
90. Wire-wound resistors are unsuitable for use at high frequencies because they
(a) create more electrical noise
(b) are likely to melt under excessive eddy current heat
(c) consume more power
(d) exhibit unwanted inductive and capacitive effects
Ans: d
91. The inductance of a coil can be increased by
(a) increasing core length
(b) decreasing the number of turns
(c) decreasing the diameter of the former
(d) choosing core material having high relative permeability
Ans: d
92. In a three-phase supply floating neutral is undesirable because it way give rise to
(a) high voltage across the load
(b) low voltage across the load
(c) unequal line voltages across the load
Ans: c
93. Which of the following waves has the highest value of peak factor ?
(a) Square wave
(b) Sine wave
(c) Half wave rectified sine wave
(d) Triangular wave
Ans: c
94. The frequency of domestic power supply in India is
(a) 200 Hz
(b) 100 Hz
(c) 60 Hz
(d) 50 Hz
Ans: d
95. The r.m.s. value of half wave rectified sine wave is 200 V. The r.m.s. value of full wave rectified AC. will be
(a) 282.8 V
(b) 141.4 V
(c) 111 V
(d) 100 V
Ans: a
96. The r.m.s. value of pure cosine function is
(a) 0.5 of peak value
(b) 0.707 of peak value
(c) same as peak value
(d) zero
Ans: b
97. Ohm is unit of all of the following except
(a) inductive reactance
(b) capacitive reactance
(c) resistance
(d) capacitance
Ans: d
98. The series ;nd parallel resonance on L-C circui’ differs in that
(a) series resistance needs a low-resistance ource for sharp rise in current
(b) series resonance needs a high-resistance source for sharp increase in current
(c) parallel resonance needs a low-resistance source for a sharp in¬crease in impedance
(d) parallel resonance needs a low-resistance source for a sharp rise in line current
Ans: a
99. The phasors for which of the following pair are 180° out of phase for VL, VC and VR?
(a) Vc and VR
(b) VL and VR
(c) Vc and VL
(d) none of the above
Ans: c
100. The frequency of an alternating current is
(a) the speed with which the alternator runs
(b) the number of cycles generated in one minute
(c) the number of waves passing through a point in one second
(d) the number of electrons passing through a point in one second
Ans: c
101. A pure capacitor connected across an A.C. voltage consumed 50 W. This is due to
(a) the capacitive reactance in ohms
(b) the current flowing in capacitor
(c) the size of the capacitor being quite big
(d) the statement is incorrect
Ans: d
102. The power factor of a D.C. circuit is always
(a) less than unity
(b) unity
(c) greater than unity
(d) zero
Ans: b
103. The product of apparent power and cosine of the phase angle between circuit voltage and current is
(a) true power
(b) reactive power
(c) volt-amperes
(d) instantaneous power
Ans: a
104. The equation of 50 Hz current sine wave having r.m.s. value of 60 A is
(a) 60 sin 25 t
(b) 60 sin 50 t
(c) 84.84 sin 3141
(d) 42.42 sin 314 t
Ans: c
105. An A.C. voltage is impressed across a pure resistance of 3.5 ohms in parallel with a pure inductance of impedance of 3.5 ohms,
(a) the current through the resistance is more
(b) the current through the resistance is less
(c) both resistance and inductance carry equal currents
(d) none of the above
Ans: c
106. In a pure inductive circuit if the supply frequency is reduced to 1/2, the current will
(a) be reduced by half
(b) be doubled
(c) be four times as high
(d) be reduced to one fourth
Ans: b
107. In a pure capacitive circuit if the supply frequency is reduced to 1/2, the current will
(a) be reduced by half
(b) be doubled
(c) be four times at high
(d) be reduced to one fourth
Ans: a
108. When an alternating current passes through an ohmic resistance the electrical power converted into heat is
(a) apparent power
(b) true power
(c) reactive power
(d) none of the above
Ans: b
109. In each of the three coils of a three phase generator, an alternating voltage having an r.m.s. value of 220 V is induced. Which of the following values is indicated by the voltmeters ?
(a) 220 V
(b) 220V3V
(c) 220/V3 V
(d) none of the above
Ans: a
110. Laminations of core are generally made of
(a) case iron
(b) carbon
(c) silicon steel
(d) stainless steel
1Two D.C. shunt generators, each with armature resistance of 0.02 ohm and field resistance of 50 ohm run in parallel and supply a total current of 1000 amperes to the load circuit. If their e.m.fs. are 270 V and 265 V, their bus bar voltage will be
(a) 270 V
(b) 267.5 V
(c) 265 V
(d) 257.4 V
Ans: b
Ans: c
2. Which of the following could be lamina-proximately the thickness of lamina-tions of a D.C. machine ?
(a) 0.005 mm
(b) 0.05 mm
(c) 0.5 m
(d) 5 m
Ans: c
3. The armature of D.C. generator is laminated to
(a) reduce the bulk
(b) provide the bulk
(c) insulate the core
(d) reduce eddy current loss
Ans: d
4. The resistance of armature winding depends on
(a) length of conductor
(b) cross-sectional area of the conductor
(c) number of conductors
(d) all of the above
Ans: d
5. The field coils of D.C. generator are usually made of
(a) mica
(b) copper
(c) cast iron
(d) carbon
Ans: b
6. The commutator segments are connected to the armature conductors by means of
(a) copper lugs
(b) resistance wires
(c) insulation pads
(d) brazing
Ans: a
7. In a commutator
(a) copper is harder than mica
(b) mica and copper are equally hard
(c) mica is harder than copper
(d) none of the above
Ans: c
8. In D.C. generators the pole shoes are fastened to the pole core by
(a) rivets
(b) counter sunk screws
(c) brazing
(d) welding
Ans: b
9. According to Fleming’s right-hand rule for finding the direction of induced e.m.f., when middle finger points in the direction of induced e.m.f., forefinger will point in the direction of
(a) motion of conductor
(b) lines of force
(c) either of the above
(d) none of the above
Ans: b
10. Fleming’s right-hand rule regarding direction of induced e.m.f., correlates
(a) magnetic flux, direction of current flow and resultant force
(b) magnetic flux, direction of motion and the direction of e.m.f. induced
(c) magnetic field strength, induced voltage and current
(d) magnetic flux, direction of force and direction of motion of conductor
Ans: b
11. While applying Fleming’s right-hand rule to And the direction of induced e.m.f., the thumb points towards
(a) direction of induced e.m.f.
(b) direction of flux
(c) direction of motion of the conductor if forefinger points in the direction of generated e.m.f.
(d) direction of motion of conductor, if forefinger points along the lines of flux
Ans: d
12. The bearings used to support the rotor shafts are generally
(a) ball bearings
(b) bush bearings
(c) magnetic bearmgs
(d) needle bearings
Ans: a
13. In D.C. generators, the cause of rapid brush wear may be
(a) severe sparking
(b) rough commutator surface
(c) imperfect contact
(d) any of the above
Ans: d
14. In lap winding, the number of brushes is always
(a) double the number of poles
(b) same as the number of poles
(c) half the number of poles
(d) two
Ans: b
15. For a D.C. generator when the number of poles and the number of armature conductors is fixed, then which winding will give the higher e.m.f. ?
(a) Lap winding
(b) Wave winding
(c) Either of (a) and (b) above
(d) Depends on other features of design
Ans: b
16. In a four-pole D.C. machine
(a) all the four poles are north poles
(b) alternate poles are north and south
(c) all the four poles are south poles
(d) two north poles follow two south poles
Ans: b
17. Copper brushes in D.C. machine are used
(a) where low voltage and high currents are involved
(b) where high voltage and small cur-rents are involved
(c) in both of the above cases
(d) in none of the above cases
Ans: a
18. A separately excited generator as compared to a self-excited generator
(a) is amenable to better voltage con-trol
(b) is more stable
(c) has exciting current independent of load current
(d) has all above features
Ans: d
19. In case of D.C. machines, mechanical losses are primary function of
(a) current
(b) voltage
(c) speed
(d) none of above
Ans: c
20. Iron losses in a D.C. machine are independent of variations in
(a) speed
(b) load
(c) voltage
(d) speed and voltage
Ans: b
21. In D.C. generators, current to the external circuit from armature is given through
(a) commutator
(b) solid connection
(c) slip rings
(d) none of above
Ans: a
23. Brushes of D.C. machines are made of
(a) carbon
(b) soft copper
(c) hard copper
(d) all of above
Ans: a
24. If B is the flux density, I the length of conductor and v the velocity of conductor, then induced e.m.f. is given by
(a)Blv
(b)Blv2
(c)Bl2v
(d)Bl2v2
Ans: a
25. In case of a 4-pole D.C. generator provided with a two layer lap winding with sixteen coils, the pole pitch will be
(a) 4
(b) 8
(c) 16
(d) 32
Ans: b
26. The material for commutator brushes is generally
(a) mica
(b) copper
(c) cast iron
(d) carbon
Ans: d
27. The insulating material used between the commutator segments is normally
(a) graphite
(b) paper
(c) mica
(d) insulating varnish
Ans: c
28. In D.C. generators, the brushes on commutator remain in contact with conductors which
(a) lie under south pole
(b) lie under north pole
(c) lie under interpolar region
(d) are farthest from the poles
Ans: c
29. If brushes of a D.C. generator are moved in order to bring these brushes in magnetic neutral axis, there will be
(a) demagnetisation only
(b) cross magnetisation as well as magnetisation
(c) crossmagnetisation as well as demagnetising
(d) cross magnetisation only
Ans: c
30. Armature reaction of an unsaturated D.C. machine is
(a) crossmagnetising
(b) demagnetising
(c) magnetising
(d) none of above
Ans: a
31. D.C. generators are connected to the busbars or disconnected from them only under the floating condition
(a) to avoid sudden loading of the primemover
(b) to avoid mechanicaljerk to the shaft
(c) to avoid burning of switch contacts
(d) all above
Ans: d
32. Eddy currents are induced in the pole shoes of a D.C. machine due to
(a) oscillating magnetic field
(b) pulsating magnetic flux
(c) relative rotation between field and armature
(d) all above
Ans: c
33. In a D.C. machine, short-circuited field coil will result in
(a) odour of barning insulation
(b) unbalanced magnetic pull producing vibrations
(c) reduction of generated voltage for which excitation has to be increased to maintain the voltage
(d) all above
Ans:
34. Equilizer rings are required in case armature is
(a) wave wound
(b) lap wound
(c) delta wound
(d) duplex wound
Ans: b
35. Welding generator will have
(a) lap winding
(b) wave winding
(c) delta winding
(d) duplex wave winding
Ans: a
36. In case of D.C. machine winding, number of commutator segments is equal to
(a) number of armature coils
(b) number of armature coil sides
(c) number of armature conductors
(d) number of armature turns
Ans: a
37. For a D.C. machines laboratory following type of D.C. supply will be suitable
(a) rotary converter
(b) mercury are rectifier
(c) induction motor D.C. generator set
(d) synchronous motor D.C. generator set
Ans: c
38. The function of pole shoes in the case of D.C. machine is
(a) to reduce the reluctance of the magnetic path
(b) to spread out the flux to achieve uniform flux density
(c) to support the field coil
(d) to discharge all the above functions
Ans: d
39. In the case of lap winding resultant pitch is
(a) multiplication of front and back pitches
(b) division of front pitch by back pitch
(c) sum of front and back pitches
(d) difference of front and back pitches
Ans: d
40. A D.C. welding generator has
(a) lap winding
(b) wave moving
(c) duplex winding
(d) any of the above
Ans: a
41. Which of the following statement about D.C. generators is false ?
(a) Compensating winding in a D.C. machine helps in commutation
(b) In a D. C. generator interpoles winding is connected in series with the armature winding
(c) Back pitch and front pitch are both odd and approximately equal to the pole pitch
(d) Equilizing bus bars are used with parallel running of D.C. shunt generators
Ans: d
42. The demagnetising component of armature reaction in a D.C. generator
(a) reduces generator e.m.f.
(b) increases armature speed
(c) reduces interpoles flux density
(d) results in sparking trouble
Ans: a
43. Magnetic field in a D.C. generator is produced by
(a) electromagnets
(b) permanent magnets
(c) both (a) and (b)
(d) none of the above
Ans: a
44. The number of brushes in a commutator depends on
(a) speed of armature
(b) type of winding
(c) voltage
(d) amount of current to be collected
Ans: d
45. Compensating windings are used in D.C. generators
(a) mainly to reduce the eddy currents by providing local short-circuits
(b) to provide path for the circulation of cooling air
(c) to neutralise the cross-magnetising effect of the armature reaction
(d) none of the above
Ans: c
46. Which of the following components of a D.C, generator plays vital role for providing direct current of a D.C. generator ?
(a) Dummy coils
(b) Commutator
(c) Eye bolt
(d) Equilizer rings
Ans: b
47. In a D.C. generator the ripples in the direct e.m.f. generated are reduced by
(a) using conductor of annealed copper
(b) using commutator with large number of segments
(c) using carbon brushes of superior quality
(d) using equiliser rings
Ans: c
48. In D.C. generators, lap winding is used for
(a) high voltage, high current
(b) low voltage, high current
(c) high voltage, low current
(d) low voltage, low current
Ans: b
49. Two generators A and B have 6-poles each. Generator A has wave wound armature while generator B has lap wound armature. The ratio of the induced e.m.f. is generator A and B will be
(a) 2 : 3
(b) 3 : 1
(c) 3 : 2
(d) 1 : 3
Ans: b
50. The voltage drop for which of the following types of brush can be expected to be least ?
(a) Graphite brushes
(b) Carbon brushes
(c) Metal graphite brushes
(d) None of the above
Ans: c
51. The e.m.f. generated by a shunt wound D.C. generator isE. Now while pole flux remains constant, if the speed of the generator is doubled, the e.m.f. generated will be
(a) E/2
(b) 2E
(c) slightly less than E
(d) E
Ans: b
52. In a D.C. generator the actual flux distribution depends upon
(a) size of air gap
(b) shape of the pole shoe
(c) clearance between tips of the ad¬jacent pole shoes
(d) all of the above
Ans:
53. The armature core of a D.C. generator is usually made of
(a) silicon steel
(b) copper
(c) non-ferrous material
(d) cast-iron
Ans: a
9.63. Satisfactory commutation of D.C. machines requires
(a) brushes should be of proper grade and size
(b) brushes should smoothly run in the holders
(c) smooth, concentric commutator properly undercut
(d) all of the above
Ans: d
54. Open circuited armature coil of a D.C. machine is
(a) identified by the scarring of the commutator segment to which open circuited coil is connected
(b) indicated by a spark completely around the commutator
(c) both (a) and (b)
(d) none of the above
Ans: c
55. In a D.C. machine, fractional pitch winding is used
(a) to increase the generated voltage
(b) to reduce sparking
(c) to save the copper because of shorter end connections
(d) due to (b) and (c) above
Ans:
56. For the parallel operation of two or more D.C. compound generators, we should ensure that
(a) voltage of the incoming generator should be same as that of bus bar
(b) polarity of incoming generator should be same as that of bus bar
(c) all the series fields should be run in parallel by means of equilizer connection
(d) series fields of all generators should be either on positive side or negative side of the armature
(e) all conditions mentioned above should be satisfied
Ans: d
57. D.C. series generator is used
(a) to supply traction load
(b) to supply industrial load at constant voltage
(c) voltage at the toad end of the feeder
(d) for none of the above purpose
Ans: c
58. Following D.C. generator will be in a position to build up without any residual magnetism in the poles
(a) series generator
(b) shunt generator
(c) compound generator
(d) self-excited generator
Ans: d
59. Interpole flux should be sufficient to
(a) neutralise the commutating self induced e.m.f.
(b) neutralise the armature reaction flux
(c) neutralise both the armature reaction flux as well as commutating e.m.f. induced in the coil
(d) perform none of the above functions
Ans: c
60. D.C. generator generally preferred for charging automobile batteries is
(a) series generator
(b) shunt generator
(c) long shunt compound generator
(d) any of’the above
Ans: c
61. In a D.C. generator the number of mechanical degrees and electrical degrees will be the same when
(a) r.p.m. is more than 300
(b) r.p.m. is less than 300
(c) number of poles is 4
(d) number of poles is 2
Ans: d
62. Permeance is the reciprocal of
(a) flux density
(b) reluctance
(c) ampere-turns
(d) resistance
Ans: b
63. In D.C. generators the polarity of the interpoles
(a) is the same as that of the main pole ahead
(b) is the same as that of the immediately preceding pole
(c) is opposite to that of the main pole ahead
(d) is neutral as these poles do not play part in generating e.m.f.
Ans: a
64. The e.m.f. generated in a D.C. generator is directly proportional to
(a) flux/pole
(b) speed of armature
(c) number of poles
(d) all of the above
Ans: b
65. In a D.C. generator the magnetic neutral axis coincides with the geometrical neutral axis, when
(a) there is no load on|he generator
(b) the generator runs on full load
(c) the generator runs on overload
(d) the generator runs on designed speed
Ans: a
66. In a D.C. generator in order to reduce sparking at brushes, the self-induced e.m.f. in the coil is neutralised by all of the following except
(a) interpoles
(b) dummy coils
(c) compensating winding
(d) shifting of axis of brushes
Ans: b
67. In D.C. generators on no-load, the air gap flux distribution in space is
(a) sinusoidal
(b) triangular
(c) pulsating
(d) flat topped
Ans: d
68. A shunt generator running at 1000 r.p.m. has generated e.m.f. as 200 V. If the speed increases to 1200 r.p.m., the generated e.m.f. will be nearly
(a) 150 V
(b) 175 V
(c) 240 V
(d) 290 V
Ans: c
69. The purpose of providing dummy coils in a generator is
(a) to reduce eddy current losses
(b) to enhance flux density
(c) to amplify voltage
(d) to provide mechanical balance for the rotor
Ans: d
70. In a shunt generator the voltage build up is generally restricted by
(a) speed limitation
(b) armature heating
(c) insulation restrictions
(d) saturation of iron
Ans:
71. If a D.C. generator fails to build up the probable cause could not be
(a) imperfect brush contact
(b) field resistance less than the critical resistance
(c) no residual magnetism in the generator
(d) faulty shunt connections tending to reduce the residual magnetism
Ans: b
72. Flashing the field of D.C. generator means
(a) neutralising residual magnetism
(b) creating residual magnetism by a D.C. source
(c) making the magnetic losses of forces parallel
(d) increasing flux density by adding extra turns of windings on poles
Ans: b
73. The e.m.f. induced in the armature of a shunt generator is 600 V. The armature resistance is 0.1 ohm. If the armature current is 200 A, the terminal voltage will be
(a) 640 V
(b) 620 V
(c) 600 V
(d) 580 V
Ans: d
74. In a D.C. generator the critical resistance refers to the resistance of
(a) brushes
(b) field
(c) armature
(d) load
Ans: b
75. To achieve sparkless commutation brushes of a D.C. generator are rockedm ahead so as to bring them
(a) just ahead of magnetic neutral axis
(b) in magnetic neutral axis
(c) just behind the magnetic neutral axis
Ans: a
76. Armature coil is short circuited by brushes when it lies
(a) along neutral axis
(b) along field axis
(c) in any of the above positions
(d) in none of the above positions
Ans: a
77. A cumulatively compounded long shunt generator when operating as a motor would be
(a) cumulatively compounded long shunt
(b) differentially compounded long shunt
(c) cumulatively compounded short shunt
(d) differentially compounded short shunt
Ans: b
78. To avoid formation of grooves in the commutator of a D.C. machine
(a) the brushes of opposite polarity should track each other
(b) the brushes of same polarity should track each other
(c) brush position has no effect on the commutator grooving
Ans: a
79. The following constitute short-circuit in the armature winding.
(a) Insulation failure between two com-mutator bars
(6) Insulation failure between two turns of a coil
(c) Two of more turns of the same coil getting grounded
(d) All of the above
Ans: d
80. The rapid wear of brushes takes place due to
(a) abrasion from dust
(b) excessive spring pressure
(c) rough commutator bars
(d) high mica insulation between com-mutation bars
(e) all of the above factors
Ans: e
81. Number of tappings for each equilizer ring is equal to
(a) number of pole pairs
(b) number of poles
(c) number of parallel paths
(d) number of commutator segments
Ans: a
82. A D.C. generator can be considered as
(a) rectifier
(b) primemover
(c) rotating amplifier
(d) power pump
Ans: c
83. In any rotating machine that part which houses the conductors and in which e.m.f. induced is to be utilised is called
(a) rotor
(b) stator
(c) field
(d) armature
Ans: d
84. In a D.C. machine stray loss is the sum of
(a) total copper loss and mechanical loss
(b) armature copper loss and iron loss
(c) shunt field copper loss and mechanical loss
(d) iron loss and mechanical loss
Ans: d
85. Lap winding is composed of
(a) any even number of conductors
(b) any odd number of conductors
(c) that even number which is exact multiple of poles + 2
(d) that even number which is exact multiple of poles
Ans: a
86. In a D.C. generator in case the resistance of the field winding is increased, then output voltage will
(a) increase
(b) decrease
(c) remain unaffected
(d) fluctuate heavily
Ans: b
87. An exciter for a turbo generator is a
(a) separately excited generator
(b) shunt generator
(c) series generator
(d) compound generator
Ans: b
88. In case of a flat compounded generator
(a) voltage generated is less than the rated voltage
(b) generated voltage is proportional to the load on the generator
(c) voltage remains constant irrespec¬tive of the load
(d) speed varies in proportion to the load on the generator
Ans: c
89. Which of the following generator will have negligible terminal voltage while running on no-load ?
(a) Series generator
(b) Shunt generator
(c) Compound generator
(d) Separately excited generator
Ans: a
90. Which of the following D.C. generators will be in a position to build up without any residual magnetism in the poles ?
(a) Series generator
(b) Shunt generator
(c) Compound generator
(d) None of the above
Ans: d
91. In over compounded generator, full load terminal voltage is
(a) almost zero
(b) less than noload terminal voltage
(c) more than noload terminal voltage
(d) equal to no-load terminal voltage
Ans: c
92. In a level compounded D.C. generator, full load terminal voltage is
(a) negligibly low
(b) equal to no-load terminal voltage
(c) more than no-load terminal voltage
(d) less than no-load terminal voltage
Ans: b
93. The terminal voltage of a D.C. shunt generator drops on load because of all of the following reasons except
(a) armature reaction
(b) armature resistance drop
(c) field weakening due to armature reaction and armature
(d) commutation
Ans: d
94. In a D.C. generator
(a) external resistance = internal char-acteristic – armature reaction
(b) internal characteristic = magnetisation characteristic – ohmic drop
(c) external characteristic = magnetisation characteristic – ohmic drop – armature reaction
(d) magnetisation characteristic = external characteristic
Ans: c
95. A sinusoidal voltage of 5 Hz is applied to the field of a shunt generator. The armature voltage wave
(a) will be zero
(b) will be of 5 Hz
(c) willbeof5xiVHz
(d) will be of v Hz 5
Ans: b
96. A 220 V D.C. generator is run at full speed without any excitation. The open circuit voltage will be
(a) zero
(b) about 2 V
(c) about 50 V
(d) 220 V
Ans: b
97. In a separately excited generator supplying rated load the armature reaction ,
(a) is always present
(b) is always absent
(c) may be sometimes present
(d) none of the above
Ans: a
98. If residual magnetism is present in a D.C. generator, the induced e.m.f. at zero speed will be
(a) zero
(b) small
(c) the same as rated voltage
(d) high
Ans: a
99. Armature reaction in a generator results in
(a) demagnetisation of leading pole tip and magnetisation of trailing pole tip
(b) demagnetisation of trailing pole tip and magnetisation of leading pole tip
(c) damagnetising the centre of all poles
(d) magnetising the centre of all poles
Ans: a
100. Following energized winding of a D.C. machine should not be opened as it would produce high inductive voltage which may be dangerous to personnel and may cause its own insulation failure.
(a) Series field
(b) Compensating field
(c) Inter pole field
(d) Shunt field
Ans: d
101. Wave winding is composed of
(a) any even number of conductors
(b) any odd number of conductors
(c) that even number which is exact multiple of poles + 2
(d) that even number which is exact multiple of poles
Ans: c
102. The critical resistance of the D.C. generator is the resistance of
(a) field
(b) brushes
(c) armature
(d) load
Ans: a
103. When two D.C. series generators are running in parallel, an equilizer bar is used
(a) to increase the speed and hence generated e.m.f.
(b) to increase the series flux
(c) so that two similar machines will pass approximately equal currents to the load
(d) to reduce the combined effect of ar-mature reaction of both machines
Ans: c
104. Which of the following generating machine will offer constant voltage on all loads ?
(a) Self-excited generator
(b) Separately excited generator
(c) Level compounded generator .
(d) All of the above
Ans: c
105. Which of the following generators will be preferred if they are required to be run in parallel ?
(a) Shunt generators
(b) Series generators
(c) Compound generators
(d) None of the above
Ans: a
106. Two generators are running in parallel. One of the generators may run as motor for which of the following reasons ?
(a) The direction of that generator is reversed
(b) The speed of that generator is increased
(c) The field of that generator is weakened
(d) That generator takes large share of loads
Ans: d
107. A D.C. generator works on the principle of
(a) Lenz’s law
(b) Ohm’s law
(c) Faraday’s law of electromagnetic induction
(d) none of the above
Ans: c
108. A series generator can self-excite
(a) only if the load current is zero
(b) only if the load current is not zero
(c) irrespective of the value of load current
(d) none of the above
Ans: b
109. A shunt generator can self-excite
(a) only if the resistance of the field circuit is less than critical value
(b) only if the resistance of the field circuit is greater than critical value
(c) irrespective of the value of the resis-tance in the field circuit
Ans: a
110. The terminal voltage of a series generator is 150 V when the load current is 5 A. If the load current is increased to 10 A, the terminal voltage will be
(a) 150 V
(b) less than 150 V
(c) greater than 150 V
(d) none of the above
Ans: c
111. The open circuit voltage of a compound generator is 250 V. At full load the terminal voltage
(a) will be less than 250 V
(b) will always be 250 V
(c) may be greater or less than 250 V
(d) none of the above
Ans: c
112. Two D.C. shunt generators, each with armature resistance of 0.02 ohm and field resistance of 50 ohm run in parallel and supply a total current of 1000 amperes to the load circuit. If their e.m.fs. are 270 V and 265 V, their bus bar voltage will be
(a) 270 V
(b) 267.5 V
(c) 265 V
(d) 257.4 V
Ans: b
113. The essential condition for parallel operation of two D.C. generators is that they have ‘
(a) same kW rating
(b) the same operation r.p.m.
(c) the same drooping voltage charac-teristics
(d) same percentage regulation
Ans: c
114. When two D.C. generators are running in parallel an equilizer bar is used
(a) to increase the series flux
(b) to increase the generated e.m.f.
(c) to reduce the combined effect of ar-mature reaction of both the machines
(d) so that the two identical machines will pass approximately equal currents to the load
Ans: d
115. With a D.C. generator which of the following regulation is preferred ?
(a) 100% regulation
(b) infinite regulation
(c) 50% regulation
(d) 1% regulation
Ans: d
116. Which generator would you prefer for feeding long D.C. transmission lines ?
(a) Series generator
(b) Shunt generator
(c) Over compound generator
(d) Flat compound generator
Ans: c
117. In a D.C. generator the critical resistance can be increased by
(a) increasing its field resistance
(b) decreasing its field resistance
(c) increasing its speed
(d) decreasing its speed
Ans: c
118. The number of armature parallel paths in a two-pole D.C. generator having duplex lap winding is
(a) 2
(b) 4
(c) 6
(d) 8
Ans: b
119. For both lap and wave windings, there are as many commutator bars as the number of
(a) slots
(b) armature conductors
(c) winding elements
(d) poles
Ans: c
120. The series field of a short-shunt D.C. generator is excited by
(a) external current
(b) armature current
(c) shunt current
(d) load current
Ans: d
121. As a result of armature reaction, the reduction in the total mutual air gap flux in a D.C. generator is approximately
(a) 40 percent
(b) 25 percent
(c) 10 percent
(d) 5 percent
Ans: d
122. Shunt generators are most suited for stable parallel operation because of their
(a) rising voltage characteristics
(b) identical voltage characteristics
(c) drooping voltage characteristics
(d) linear voltage characteristics
Ans: c
123. The main factor which leads to unstable parallel operation of flat and over compounded generators is
(a) their rising voltage characteristics
(b) unequal number of turns in their series field windings
(c) unequal speed regulation of their primemovers
(d) unequal series field resistances
Ans: a
124. If a self excited D.C. generator after being installed, fails to build up on its first trial run, the first thing to do is to
(a) reverse the field connections
(b) increase the field resistance
(c) increase the speed of primemover
(d) check armature insulation resis¬tance
Ans: a
125.The essential condition for parallel operation of two D.C. generators is that they have ‘
(a) same kW rating
(b) the same operation r.p.m.
(c) the same drooping voltage charac-teristics
(d) same percentage regulation
Ans: c
ONGC Fluid Mechanics questions with answers,All IT and Non IT (PSU companies) BHEL BEL,HAL,HIL,etcc,bank,IBPS,PO,clerical and all banks solved questions with answerrs and detailed explanations,ONGC model question for practice,ONGC practice question for all engineering streams,ONGC topicwise questions 1. Pascal-second is the unit of a) pressure b) kinematic viscosity c) dynamic viscosity d) surface tension Ans: c 2. An ideal fluid is a) one which obeys Newton’s law of viscosity b) frictionless and incompressible c) very viscous d) frictionless and compressible Ans: b 3. The unit of kinematic viscosity is a) gm/cm-sec2 b) dyne-sec/cm2 c) gm/cm2-sec d) cm2/sec Ans: d 4. If the dynamic viscosity of a fluid is 0.5 poise and specific gravity is 0.5, then the kinematic viscosity of that fluid in stokes is a) 0.25 b) 0.50 c) 1.0 d) none of the above Ans: c 5. The viscosity of a gas a) decreases with increase in temperature b) increases with increase in temperature c) is independent of temperature d) is independent of pressure for very high pressure intensities Ans: b 6. Newton’s law of viscosity relates a) intensity of pressure and rate of angular deformation b) shear stress and rate of angular deformation c) shear stress, viscosity and temperature d) viscosity and rate of angular deformation Ans: b 7. An open tank contains 1 m deep water with 50 cm depth of oil of specific gravity 0.8 above it. The intensity of pressure at the bottom of tank will be a) 4 kN/m2 b) 10 kN/m2 c) 12 kN/m2 d) 14 kN/m2 Ans: d 8. The position of center of pressure on a plane surface immersed vertically in a static mass of fluid is a) at the centroid of the submerged area b) always above the centroid of the area c) always below the centroid of the area d) none of the above Ans: c 9. The total pressure on a plane surface inclined at an angle 9 with the horizontal is equal to a) PA b) pA sin 9 c) pA cos 9 d) pA tan 9 where p is pressure intensity at centroid of area and A is area of plane surface. Ans: a 10. A vertical rectangular plane surface is submerged in water such that its top and bottom surfaces are 1.5 m and 6.0 m res-pectively below the free surface. The position of center of pressure below the free surface will be at a distance of a) 3.75 m b) 4.0 m c) 4.2m d) 4.5m Ans: c 11. Centre of buoyancy always a) coincides with the centre of gravity b) coincides with the centroid of the volume of fluid displaced c) remains above the centre of gravity d) remains below the centre of gravity Ans: b 12. If the weight of a body immersed in a fluid exceeds the buoyant force, then the body will a) rise until its weight equals the buoyant force b) tend to move downward and it may finally sink c) float d) none of the above Ans: b 13. Metacentric height for small values of angle of heel is the distance between the a) centre of gravity and centre of buoy-ancy b) centre of gravity and metacentre c) centre of buoyancy and metacentre d) free surface and centre of buoyancy Ans: b 14. A floating body is said to be in a state of stable equilibrium a) when its metacentric height is zero b) when the metacentre is above the centre of gravity c) when the metacentre is below the centre of gravity d) only when its centre of gravity is below its centre of buoyancy Ans: b 15. The increase in meta centric height i) increases stability ii) decreases stability iii) increases comfort for passengers iv) decreases comfort for passengers The correct answer is a) (i) and (iii) b) (i)and(iv) c) (ii) and (iii) d) (ii) and (iv) Ans: b 16. A rectangular block 2 m long, 1 m wide and 1 m deep floats in water, the depth of immersion being 0.5 m. If water weighs 10 kN/m3, then the weight of the block is a) 5kN b) lOkN c) 15 kN d) 20 kN Ans: b 17. The point in the immersed body through which the resultant pressure of the liquid may be taken to act is known as a) center of gravity b) center of buoyancy c) center of pressure d) metacentre Ans: c 18. If a vessel containing liquid moves downward with a constant acceleration equal to ‘g’ then a) the pressure throughout the liquid mass is atmospheric b) there will be vacuum in the liquid c) the pressure in the liquid mass is greater than hydrostatic pressure d) none of the above Ans: a 19. When a liquid rotates at a constant angular velocity about a vertical axis as a rigid body, the pressure intensity varies a) linearly with radial distance b) as the square of the radial distance c) inversely as the square of the radial distance d) inversely as the radial distance Ans: b 20. An open cubical tank of 2 m side is filled with water. If the tank is rotated with an acceleration such that half of the water spills out, then the acceleration is equal to a) g/3 b) g/2 c) 2g/3 d) g Ans: d 21. A right circular cylinder open at the top is filled with liquid and rotated about its vertical axis at such a speed that half the liquid spills out, then the pressure intensity at the center of bottom is a) zero b) one-fourth its value when cylinder was full c) one-half its value when cylinder was full d) cannot be predicted from the given data Ans: a 22. The horizontal component of force on a curved surface is equal to the a) product of pressure intensity at its centroid and area b) force on a vertical projection of the curved surface c) weight of liquid vertically above the curved surface d) force on the horizontal projection of the curved surface Ans: b 23. A closed tank containing water is moving in a horizontal direction along a straight line at a constant speed. The tank also contains a steel ball and a bubble of air. If the tank is decelerated horizontally, then i) the ball will move to the front ii) the bubble will move to the front iii) the ball will move to the rear iv) the bubble will move to the rear Find out which of the above statements are correct ? a) (i) and (ii) b) (i)and(iv) c) (ii) and (iii) d) (iii) and (iv) Ans: b 24. The eddy viscosity for turbulent flow is a) a function of temperature only b) a physical property of the fluid. c) dependent on the flow d) independent of the flow Ans: c 25. Flow at constant rate through a tapering pipe is i) steady flow ii) uniform flow iii) unsteady flow iv) non-uniform flow The correct answer is a) (i) and (ii) b) (i)and(iv) c) (ii) and (iii) d) (ii) and (iv) Ans: b 26. In a two dimensional incompressible steady flow around an airfoil, the stream lines are 2 cm apart at a great distance from the airfoil, where the velocity is 30 m/sec. The velocity near the airfoil, where the stream lines are 1.5 cm apart, is a) 22.5 m/sec. b) 33 m/sec. c) 40 m/sec. d) 90 m/sec. Ans: c 27. When the velocity distribution is uniform over the cross-section, the correction factor for momentum is a) 0 b) 1 c) 4/3 d) 2 Ans: b 28. Least possible value of correction factor for i) kinetic energy is zero ii) kinetic energy is 1 iii) momentum is zero iv) momentum is 1 The correct statements are a) (i) and (iii) b) (ii) and (iii) c) (i) and (iv) d) (ii) and (iv) Ans: d 29. If the velocity is zero over half of the cross-sectional area and is uniform over the remaining half, then the momentum correction factor is a) 1 b) 4/3 c) 2 d) 4 Ans: c 30. If velocity is zero over l/3rd of a cross-section and is uniform over remaining 2/3rd of the cross-section, then the correction factor for kinetic energy is a) 4/3 b) 3/2 c) 9/4 d) 27/8 Ans: c 31. The continuity equation pi V,A,= p2V2A2 is based on the following assumption regarding flow of fluid a) steady flow b) uniform flow c) incompressible flow d) frictionless flow where pi and p2 are mass densities. Ans: a 32. Which of the following velocity potentials satisfies continuity equation ? a) x2y b) x2-y2 c) cosx d) x2 + y2 Ans: b 33. The motion of air mass in a tornado is a a) free vortex motion b) forced vortex motion c) free vortex at center and forced vortex outside d) forced vortex at center and free vortex outside Ans: d 34. In a forced vortex motion, the velocity of flow is a) directly proportional to its radial distance from axis of rotation b) inversely proportional to its radial distance from the axis of rotation c) inversely proportional to the square of its radial distance from the axis of rotation d) directly proportional to the square of its radial distance from the axis of rotation Ans: a 35. Stream lines and path lines always coincide in case of a) steady flow b) laminar flow c) uniform flow d) turbulent flow Ans: a 36. Equation of continuity is based on the principle of conservation of a) mass b) energy c) momentum d) none of the above Ans: a 37. In steady flow of a fluid, the total accele ration of any fluid particle a) can be zero b) is never zero c) is always zero d) is independent of coordinates Ans: a 38. The pitot tube is used to measure a) velocity at stagnation point b) stagnation pressure c) static pressure d) dynamic pressure Ans: b 39. Hot wire anemometer is used to measure a) discharge b) velocity of gas c) pressure intensity of gas d) pressure intensity of liquid Ans: b 40. The theoretical value of coefficient of contraction of a sharp edged orifice is a) 0.611 b) 0.85 c) 0.98 d) 1.00 Ans: a 41. Which of the following is used to measure the discharge ? a) current meter b) venturimeter c) pitot tube d) hotwire anemometer Ans: b 42. Select the incorrect statement. a) The pressure intensity at vena contracta is atmospheric. b) Contraction is least at vena contracta. c) Stream lines are parallel throughout the jet at vena contracta. d) Coefficient of contraction is always less than one. Ans: c 43. Size of a venturimeter is specified by a) pipe diameter b) throat diameter c) angle of diverging section d) both pipe diameter as well as throat diameter Ans: a 44. Due to each end contraction, the discharge of rectangular sharp crested weir is reduced by a) 5% b) 10% c) 15% d) 20% Ans: a 45. The discharge through a V- notch varies as a) H1/2 b) H3’2 c) H5/2 d) H5’4 where H is head. Ans: c 46. Which of the following is an incorrect statement ? a) Coefficient of contraction of a venturimeter is unity. b) Flow nozzle is cheaper than venturimeter but has higher energy loss. c) Discharge is independent of orientation of venturimeter whether it is horizontal, vertical or inclined. d) None of the above statement is correct. Ans: d 47. Coefficient of velocity of venturimeter a) is independent of Reynolds number b) decreases with higher Reynolds number c) is equal to the coefficient of discharge of venturimeter d) none of the above Ans: c 48. The pressure at the summit of a syphon is a) equal to atmospheric b) less than atmospheric c) more than atmospheric d) none of the above Ans: b 49. Ay between two stream lines represents a) velocity b) discharge c) head d) pressure Ans: b 50. Coefficient of velocity for Borda’s mouth piece running full is a) 0.611 b) 0.707 c) 0.855 d) 1.00 Ans: b 51. Coefficient of discharge for a totally submerged orifice as compared to that for an orifice discharging free is a) slightly less b) slightly more c) nearly half d) equal Ans: a 52. The major loss of energy in long pipes is due to a) sudden enlargement b) sudden contraction c) gradual contraction or enlargement d) friction Ans: d 53. Coefficient of contraction for an external cylindrical mouthpiece is a) 1.00 b) 0.855 c) 0.7H d) 0.611 Ans: a 54. Which of the following has highest coefficient of discharge ? a) sharp edged orifice b) venturimeter c) Borda’s mouthpiece running full d) CipoUetti weir Ans: b 55. In a Sutro weir, the discharge is proportional to a) H1/2 b) H3/2 c) H5/2 d) H where H is head. Ans: d 56. The discharge over a broad crested weir is maximum when the depth of flow is a) H/3 b) H/2 c) 2 H/5 d) 2 H/3 where H is the available head. Ans: d 57. Which of the following statements is correct? a) Lower critical Reynolds number is of no practical significance in pipe flow problems. b) Upper critical Reynolds number is significant in pipe flow problems. c) Lower critical Reynolds number has the value 2000 in pipe flow d) Upper critical Reynolds number is the number at which turbulent flow changes to laminar flow. Ans: a 58. For a sphere of radius 15 cm moving with a uniform velocity of 2 m/sec through a liquid of specific gravity 0.9 and dynamic viscosity 0.8 poise, the Reynolds number will be a) 300 b) 337.5 c) 600 d) 675 Ans: d 59. The shear stress distribution for a fluid flowing in between the parallel plates, both at rest, is a) constant over the cross section b) parabolic distribution across the section c) zero at the mid plane and varies linearly with distance from mid plane d) zero at plates and increases linearly to midpoint Ans: c 60. If x is the distance from leading edge, then the boundary layer thickness in laminar flow varies as a) x b) x c) x d) x/7 Ans: a 61. Stanton diagram is a a) log-log plot of friction factor against Reynolds number b) log-log plot of relative roughness against Reynolds number c) semi-log plot of friction factor against Reynolds number d) semi-log plot of friction factor against relative roughness Ans: a 62. The depth ‘d’ below the free surface at which the point velocity is equal to the average velocity of flow for a uniform laminar flow with a free surface, will be a) 0.423 D b) 0.577 D c) 0.223 D d) 0.707 D where D is the depth of flow. Ans: b 63. The boundary layer thickness in turbulent flow varies as a) x”7 b) x,/2 c) x4/5 d) x3/5 where x is the distance from leading edge. Ans: c 64. The distance y from pipe boundary, at which the point velocity is equal to average velocity for turbulent flow, is a) 0.223 R b) 0.423 R c) 0.577 R d) 0.707 R where R is radius of pipe. Ans: a 65. If a sphere of diameter 1 cm falls in castor oil of kinematic viscosity 10 stokes, with a terminal velocity of 1.5 cm/sec, the coefficient of drag on the sphere is a) less than 1 b) between 1 and 100 c) 160 d) 200 Ans: c 66. In case of an airfoil, the separation of flow occurs a) at the extreme rear of body b) at the extreme front of body c) midway between rear and front of body d) any where between rear and front of body depending upon Reynolds number Ans: a 67. When an ideal fluid flows past a sphere, a) highest intensity of pressure occurs around the circumference at right angles to flow b) lowest pressure intensity occurs at front stagnation point c) lowest pressure intensity occurs at rear stagnation point d) total drag is zero Ans: d 68. With the same cross-sectional area and immersed in same turbulent flow, the largest total drag will be on a) a circular disc of plate held normal to flow b) a sphere c) a cylinder d) a streamlined body Ans: a 69. In which of the following the friction drag is generally larger than pressure drag? a) a circular disc or plate held normal to flow b) a sphere c) a cylinder d) an airfoil Ans: d 70. For hydro-dynamically smooth boundary, the friction coefficient for turbulent flow is a) constant b) dependent only on Reynolds number c) a function of Reynolds number and relative roughness d) dependent on relative roughness only Ans: b 71. The value of friction factor ‘f’ for smooth pipes for Reynolds number 106 is approximately equal to a) 0.1 b) 0.01 c) 0.001 d) 0.0001 Ans: b 72. For laminar flow in a pipe of circular cross-section, the Darcy’s friction factor f is a) directly proportional to Reynolds number and independent of pipe wall roughness b) directly proportional to pipe wall roughness and independent of Reynolds number c) inversely proportional to Reynolds number and indpendent of pipe wall roughness d) inversely proportional to Reynolds number and directly proportional to pipe wall roughness Ans: c 73. Separation of flow occurs when a) the pressure intensity reaches a minimum b) the cross-section of a channel is reduced c) the boundary layer comes to rest d) all of the above Ans: c 74. The ratio of average velocity to maximum velocity for steady laminar flow in circular pipes is a) 1/2 b) 2/3 c) 3/2 d) 2 Ans: a 75. The distance from pipe boundary, at which the turbulent shear stress is one-third die wall shear stress, is a) 1/3 R b) 1/2 R c) 2/3 R d) 3/4R where R is the radius of pipe. Ans: a 76. The discharge of a liquid of kinematic viscosity 4 cm2/sec through a 8 cm dia-meter pipe is 3200n cm7sec. The type of flow expected is a) laminar flow b) transition flow c) turbulent flow d) not predictable from the given data Ans: a 77. The Prartdtl mixing length is a) zero at the pipe wall b) maximum at the pipe wall c) independent of shear stress d) none of the above Ans: a 78. The velocity distribution for laminar flow through a circular tube a) is constant over the cross-section b) varies linearly from zero at walls to maximum at centre c) varies parabolically with maximum at the centre d) none of the above Ans: c 79. A fluid of kinematic viscosity 0.4 cm2/sec flows through a 8 cm diameter pipe. The maximum velocity for laminar flow will be a) less than 1 m/sec b) 1 m/sec c) 1.5 m/sec d) 2 m/sec Ans: b 80. The losses are more in a) laminar flow b) transition flow c) turbulent flow d) critical flow Ans: c 81. The wake a) always occurs before a separation point b) always occurs after a separation point c) is a region of high pressure intensity d) none of the above Ans: b 82. The maximum thickness of boundary layer in a pipe of radius r is a) 0 b) r/2 c) r d) 2r Ans: c 83. The hydraulic grade line is a) always above the centre line of pipe b) never above the energy grade line c) always sloping downward in the direction of flow d) all of the above Ans: b 84. Two pipe systems are said to be equivalent when a) head loss and discharge are same in two systems b) length of pipe and discharge are same in two systems c) friction factor and length are same in two systems d) length and diameter are same in two systems Ans: a 85. In series-pipe problems a) the head loss is same through each pipe b) the discharge is same through each pipe c) a trial solution is not necessary d) the discharge through each pipe is added to obtain total discharge Ans: b 86. Select the correct statement. a) The absolute roughness of a pipe de-creases with time. b) A pipe becomes smooth after using for long time. c) The friction factor decreases with time. d) The absolute roughness increases with time. Ans: d 87. A valve is suddenly closed in a water main in wl.ich the velocity is 1 m/sec and velocity of pressure wave is 981 m/ sec. The inertia head at the valve will be a) 1 m b) 10m c) 100m d) none of the above Ans: c 88. The speed of a pressure wave through a pipe depends upon a) the length of pipe b) the viscosity of fluid c) the bulk modulus for the fluid d) the original head Ans: c 89. When time of closure tc = L/v0 (where L is length of pipe and v0 is speed of pressure wave), the portion of pipe length subjected to maximum head is a) L/4 b) L/3 c) L/2 d) L Ans: a 90. If the elevation of hydraulic grade line at the junction of three pipes is above the elevation of reservoirs B and C and below reservoir A, then the direction of flow will be a) from reservoir A to reservoirs B and C b) from reservoir B to reservoirs C and A c) from reservoir C to reservoirs A and B d) unpredictable Ans: c 91. The length of a pipe is 1 km and its diameter is 20 cm. If the diameter of an equivalent pipe is 40 cm, then its length is a) 32 km b) 20 km c) 8 km d) 4 km Ans: a 92. Two pipes of same length and diameters d and 2d respectively are connected in series. The diameter of an equivalent pipe of same length is a) less than d b) between d and 1.5 d c) between 1.5 d and 2d d) greater than 2d Ans: a 93. The horse power transmitted through a pipe is maximum when the ratio of loss of head due to friction and total head supplied is a) 1/3 b) 1/4 c) 1/2 d) 2/3 Ans: a 94. The boundary layer thickness at a distance of l m from the leading edge of a flat plate, kept at zero angle of incidence to the flow direction, is O.l cm. The velocity outside the boundary layer is 25 ml sec. The boundary layer thickness at a distance of 4 m is a) 0.40 cm b) 0.20 cm c) 0.10 cm d) 0.05 cm Assume that boundary layer is entirely laminar. Ans: b 95. Drag force is a function of i) projected area of the body ii) mass density of the fluid iii) velocity of the body The correct answer is a) (i) and (ii) b) (i) and (iii) c) (ii) and (iii) d) (i), (ii) and (iii) Ans: d 96. The correct relationship among displacement thickness d, momentum thickness m and energy thickness e is a) d > m > e b) d > e > m c) e > m > d d) e > d > m Ans: d 97. For laminar flow in circular pipes, the Darcy’s friction factor f is equal to a) 16/Re b) 32/ Re c) 64/ Re d) none of the above where R,, is Reynolds number. Ans: c 98. Surge wave in a rectangular channel is an example of i) steady flow ii) unsteady flow iii) uniform flow iv) non-uniform flow The correct answer is a) (i) and (iii) b) (ii) and (iii) c) (i) and (:v) d) (ii) and (iv) Ans: d
16 What do you understand by “order of a reaction”? Indicate the methods available for determining the order of a given reaction.
17 An elementary reaction A à R à S, takes place in a mixed flow reactor. Find the condition for maximum concentration of R. What is its value? (Assume no R and S initially)
18 “There exists a conversion below which the performance of a mixed flow reactor is better or at least equal to that of plug flow reactor for adiabatic exothermic reaction” – Explain.
19 Discuss briefly the shrinking core model used for describing the global rate of fluid-solid non-catalytic reactions, and outline design methods for such reactions.
Explain the different models for gas-solid non-catalytic reactions of the type,
A(g) + bB(s) à E(g) + F(s)
20 Discuss the differences between chemisorption and physical adsorption and their role in catalytic reactions.
21 Discuss the effect of mass and heat transfer on the performance of industrial catalytic reactors.
22 Compare the performance of fluidized-bed, trickle-bed and slurry reactors.
23 A first order reaction is to be treated in a series of two mixed reactors. Show that the total volume of the two reactors is minimum when the reactors are equal in size.
What is understood by ‘optimum temperature progression’? Illustrate with an example of reversible exothermic reaction using a given feed material.
24 Compare the performance of an adiabatic and an isothermal reactor, choosing an example of an exothermic reaction.
25 Determine the activation energy and the frequency factor from the following data for the bimolecular formation of methyl ethyl ether.
ToC 0 6 12 18 24 30
10 k, 5.6 11.8 24.5 48.8 100 208
litres/gmol.sec
26 what do you understand by these two terms?
27 The homogeneous gas-phase reaction A à 3B has a rate constant of k = 0.5 min-1. Obtain an expression for the total pressure in a constant volume reactor as a function of time t (min) and the initial pressure po. What will be the effect of 50% inerts present initially along with pure A?
28 Under appropriate conditions, the following reaction takes place.
With k1 = k2 = 0.1 min-1. R is to be produced from 1000 litres/hour of feed with CAO = 1 gmol/litre and CRO = CSO = 0. What size of plug flow reactor will maximize the yield of R? What is the concentration of R in the effluent stream of this of this reactor?
29 A reactor decomposing by a second order mechanism is passed through a PFR and CSTR of equal volumes in series. The effluent from the CSTR contains 1% of the original reactant. How much of the original reactant would be left in the process stream, if it passed through the CSTR and then through the PFR? There is no change in density or temperature of the process stream.
30 Establish the kinetics of the thermal decomposition of Nitrous oxide from the following data and find the reaction rate at 990oC and an initial pressure of 200 mm Hg.
t, min 20 53 100
% decomposition 23 50 73
31 An elementary liquid phase reaction (irreversible first order) A à R, takes place in a PFR and the conversion is 96%. If a mixed flow reactor of 10 times as large as the PFR is hooked up in parallel with the existing unit, by what fraction could the production be increased for the same 96% conversion?
32 Determine the activation energy and frequency factor using Arrhenius and Transition state theories from the following data:
k, min-1 0.001 0.05
T oC 0.0 100.0
33 Sulfuryl chloride vapors are heated in a closed vessel for 45 min at 320oC and 1 atm initial pressure. The dissociation of SO2Cl2 to SO2 and Cl2 is a first order reaction. The reaction velocity constant is 0.00130 min-1. Calculate the percentage decomposition of SO2Cl2 and the time required to decompose 80% of SO2Cl2.
34 A homogeneous liquid phase reaction A à R takes place with 50% conversion in a mixed reactor. The reaction is elementary second order.
What will be the conversion if the original reactor is replaced by one which is six times as large as the original reactor – all else remaining unchanged?
What will be the conversion if the original reactor is replaced by a plug flow reactor of equal size – all else remaining unchanged?
35 A liquid is to be hydrolyzed in three mixed reactors connected in series. If each reactor has a volume of 2 litres and the feed rate to the first reactor is 500 cc/min, determine the percent hydrolysis accomplished in the three reactors.
Data: Rate of hydrolysis = r = 0.16 gmol/cc.min
36 The thermal decomposition of nitrous oxide (N2O) in the gas phase at 1030oK is studied in a constant volume vessel at various initial pressures of N2O. The half-life data so obtained are as follows:
po (mm Hg) 52.5 139 290 360
t1/2 (sec) 860 470 255 212
2N2O à 2N2 + O2
37 Determine the rate equation that fits the data.
The decomposition of NO2 follows a second order rate equation. Data at different temperatures are as follows:
T (K) 592 603 627 651.5 656
k (cm3/gmol.sec)522 755 1700 4020 5030
Compute the energy of activation E from the data. The reaction is 2NO2 à 2NO + O2
38Two stirred tanks of volume V1 and 2V1 are available for carrying out a first order irreversible reaction at constant density and temperature. If the flow rate of the feed stream is Q, which of the following arrangements would give the highest production rate of the product?
Parallel operation of the two reactors, with equal average residence times.
Parallel operation, with different average residence times.
Series operation, with feed stream entering the larger reactor.
Series operation, with feed entering the smaller reactor.
39 The gas phase decomposition of A takes place according to the irreversible reaction, A à 3P. The kinetics of the reaction was studied by measuring the increase in pressure in a constant volume reaction vessel. At 504oC and an initial pressure of 312 mm Hg, the following data were obtained:
Time (Sec) 390 777 1195 3155 a
Total pressure (mm Hg) 408 488 562 779 931
Test for a first order reaction.
Calculate the value of the specific reaction rate at 504oC.
The reaction A d B ‡ C has the rate equations.
rA = 0.4 CA, rB = 0.3 CB – 0.4 CC
40 Three tanks of different sizes are available. At the desired production rate, the residence times of 5 min, 10 min and 15 min, are maintained in the successive stages of the CSTR battery. The feed concentrations are CAo = 0.9 ; CBo = 1.2 and CCo = 0
41 Find the concentration of B in the effluent from each tank.
Find the specific reaction rate and order of reaction for thermal decomposition of nitrous oxide on gold at 990oC and initial pressure of 200 mm Hg.
t, min 20 53 100
% decomposition 32& 50 73
The decomposition of phosphine is irreversible and first order at 650oC.
4PH3(g) à P4(g) + 6H2(g)
The rate constant (sec-1) is reported as
log k = (-18993/T ) + 2 log T + 12.13
where T is in oK.
In a closed vessel (constant volume) initially containing phosphine at 1 atm pressure, what will be the pressure after 50, 100 and 500 sec. The temperature is maintained at 650oC.
The kinetics of an aqueous phase decomposition of A is investigated in two CSTR’s in series, the first having half the volume of the second. At steady state with a feed concentration of 4 gmol/lit., and mean residence time of 65 sec in the second reactor, the concentration of feed to second from the first is found to be 2 gmol/lit., while that of the stream leaving the second is 1 gmol/lit. Find the suitable kinetic rate expression.
Two small samples of solids are introduced into a constant environment oven and kept there for 1 hour. Under these conditions 4 mm particles are 58% converted and 2 mm particles are 87.5% converted. Find
the rate controlling mechanism for the conversion of solids.
Time needed for the complete conversion of 1 mm particles in this oven.
The catalytic reaction A Û M + N takes place in a reactor where the effect of diffusive mass transfer may be neglected. The following steps may be considered
Adsorption of A
Adsorbed A reacts with a vacant active centre to produce adsorbed M and N
Desorption of M and N.
Assuming the surface reaction is rate controlling, develop the overall rate equation.
The solid-catalyzed decomposition of gaseous A proceeds as follows:
A à R -rA = kCA2
A tubular pilot plant reactor packed with 2 litres of catalyst is fed 2 m3/hr of pure A at 300oC and 20 atm. Conversion of reactant is 65%.
In a large plant, it is desired to treat 100 m3/hr of feed gases at 40 atm and 300oC containing 60% A and 40% inerts to obtain 85% conversion of A. Find the internal volume of the reactor required.
A batch of solids of uniform size is treated by gas in a uniform environment. Solid is converted to give a non-flaking product according to the shrinking core model. Conversion is about 7/8 for a reaction time of one hour, and conversion is complete in two hours. What mechanism is rate controlling?
The following kinetic data on the reaction A à R are obtained in an experimental packed bed reactor using various amounts of catalyst and a fixed feed rate of FAO = 10 kmol/hr.
W kg. catalyst 1 2 3 4 5
6 7
XA 0.12 0.2 0.27 0.33 0.37 0.41
0.44
ONGC free solved placement papers ONGC chemical engg questions for practice ONGC models questions for chemical engineering questions
1. The fluid property, due to which, mercury does not wet the glass is A. surface tension B. viscosity C. cohesion D. adhesion Answer: Option A 2. Laminar flow of a Newtonion fluid ceases to exist, when the Reynolds number exceeds A. 4000 B. 2100 C. 1500 D. 3000 . Answer: Option B 3. When the momentum of one fluid is used for moving another fluid, such a device is called a/an A. jet pump B. blower C. acid egg D. none of these . Answer: Option A 4. The normal stress is the same in all directions at a point in a fluid, when the fluid is A. non-viscous. B. incompressible. C. both (a) and (b). D. having no motion of one fluid layer relative to the other. . Answer: Option D 5. Head developed by a centrifugal pump depends on its A. speed B. impeller diameter C. both (a) and (b) D. neither (a) nor (b) . Answer: Option C 6. Hydraulic mean depth (Dm) for a circular pipe of diameter ‘D’ flowing full is 0.25 D. For a circular channel, at Dm = 0.3 D, gives the condition for the maximum A. flow rate B. mean velocity C. both ‘a’ & ‘b’ D. neither ‘a’ nor ‘b’ . Answer: Option B 7. The head loss in turbulent flow in a pipe varies A. as velocity B. as (velocity)2 C. inversely as the square of diameter D. inversely as the velocity . Answer: Option B 8. Most commonly used joint in the underground pipe lines is the A. sleevejoint B. coupling C. flange D. expansion joint . Answer: Option A 9. Schedule number of a pipe, which is a measure of its wall thickness, is given by A. 1000 P’/S B. 100 P’/S C. 1000 S/P’ D. 10000 P’/S . Answer: Option A 10. The net positive suction head (NPSH) of a centrifugal pump is defined as the sum of the velocity head and the pressure head at the A. discharge. B. suction. C. suction minus vapor pressure of the liquid at suction temperature. D. discharge minus vapor pressure of the liquid at the discharge temperature. . Answer: Option C 11. With increasing flow rate, the hydraulic efficiency of a centrifugal pump A. monotonically decreases. B. decreases and then increases. C. remains constant. D. increases and then decreases. . Answer: Option A 12. The velocity profile for turbulent flow through a closed conduit is A. logarithmic B. parabolic C. hyperbolic D. linear . Answer: Option A 13. In case of hydraulically smooth pipe, the resistance to flow depends only on the Reynolds number, whereas for a hydraulically rough pipe, the resistance to flow is governed by the relative roughness. Two pipes are said to have the same hydraulic roughness, when they have equal values of A. relative roughness. B. absolute roughness. C. friction co-efficient for flows at equal Reynold number. D. all (a), (b) & (c). . Answer: Option C 14. Water hammer in a pipeline results from the A. bursting of pipelines due to closure by a valve. B. rapid pressure change due to a rapid change in the rate of flow. C. pressure increase due to closure of a valve resulting in decrease in rate of flow. D. none of these. . Answer: Option B 15. Molten soap mass is transported by a __________ pump. A. diaphragm B. reciprocating C. gear D. centrifugal . Answer: Option C 16. Which of the following denotes the effect of compressibility in fluid flow ? A. Weber number B. Mach number C. Euler number D. Reynolds number . Answer: Option B 17. Nominal size of the discharge pipe of a pump is usually __________ the nominal size of the inlet pipe. A. smaller than B. larger than C. same as D. twice . Answer: Option A 18. The terminal velocity of a small sphere settling in a viscous fluid varies as the A. first power of its dimeter. B. inverse of the fluid viscosity. C. inverse square of the diameter. D. square of the difference in specific weights of solid & fluid. . Answer: Option B 19. If the discharge of a centrifugal pump is throttled, then its suction lift A. increases B. decreases C. remains unchanged D. data insufficient to predict . Answer: Option A 20. Foot valves provided in pumps are __________ valves. A. relief B. three/four way C. pressure reducing D. directional control . Answer: Option D 21. At high Reynolds number A. inertial forces control and viscous forces are unimportant. B. viscous forces predominate. C. inertial forces are unimportant and viscous forces control. D. none of these. . Answer: Option A 22. Power loss in an orificemeter is __________ that in a venturimeter. A. less than B. same as C. more than D. data insufficient, cannot be predicted . Answer: Option C 23. The terminal velocity of a particle moving through a fluid varies as dpn. What is the value of n’ for Newton’s law regime ? A. 0.5 B. 1 C. 1.5 D. 3 . Answer: Option A 24. What is the normal range of exit cone angle of a venturimeter ? A. 2 to 5 B. 7 to 15 C. 15 to 25 D. >25 . Answer: Option B 25. The dimension of dynamic viscosity is A. ML-1T-1 B. L2T-1 C. LT-2 D. ML-1T-2 . Answer: Option A .: 26. A particle A of diameter 10 microns settles in an oil of specific gravity 0.9 and viscosity 10 poise under Stoke’s law. A particle B with diameter 20 microns settling in the same oil will have a settling velocity A. same as that of A. B. one fourth as that of A. C. twice as that of A. D. four times as that of A. . Answer: Option B 27. The pitot static tube does not measure the __________ pressure. A. static B. total C. difference in static & dynamic D. all (a), (b) and (c) . Answer: Option D 28. The fluid in which the shearing stress within it is proportional to the velocity gradient across the sheared section, is called a __________ fluid. A. Bingham B. Newtonion C. perfect D. none of these . Answer: Option C . 29. In fluid flow, cavitation is caused, if the A. fluid velocity decreases to zero. B. total energy decreases. C. both (a) and (b). D. flow pressure approaches its vapor pressure at the prevailing temperature. . Answer: Option D 30. The ratio of the depth of flow to the hydraulic radius for the most economical trapezoidal section, in open channel flow is A. 0.5 B. 1 C. 1.5 D. 2 . Answer: Option D 31. The drag co-efficient for a bacterium moving in water at 1 mm/s, will be of the following order of magnitude (assume size of the bacterium to be 1 micron and kinematic viscosity of water to be 10-6m2/s). A. 24000 B. 24 C. 0.24 D. 0.44 . Answer: Option D 32. For Laminar flow through a packed bed, the pressure drop is proportional to (Vs is the superficial liquid velocity and Dp is the particle diameter) A. Vs/Dp2 B. Vs2/Dp2 C. Vs2/Dp3 D. Vs/Dp3 . Answer: Option A 33. The maximum delivery pressure of compressors can be upto __________ atmospheres. A. 10 B. 100 C. 250 D. 1000 . Answer: Option D 34. Dimension of surface tension is(where, F = force, L = length) A. FLT-1 B. F-1 . L C. F.L-2 D. F-2 . L . Answer: Option A 35. Which of the following is not a dimension-less parameter ? A. Euler number B. Specific gravity C. Fanning friction factor D. None of these . Answer: Option D 36. Co-efficient of velocity is __________ the coefficient of discharge. A. less than B. more than C. equal to D. not related to . Answer: Option B 37. All pipes of a particular nominal size have the same A. inside diameter B. outside diameter C. thickness D. none of these . Answer: Option B 38. For the transfer of solution of thick slurry, the pump used is a __________ pump. A. reciprocating B. gear C. diaphragm D. centrifugal . Answer: Option C 39. Which of the following is not concerned with the fluid-particle interaction ? A. Drag co-efficient B. Froude number C. Galileo number D. Weber number . Answer: Option D 40. Maximum theoretical suction lift for water at 15°C by a centrifugal pump is 34 ft. The same for water at 90°C will be __________ ft. A. 40 B. 34 C. 8 D. 37 . Answer: Option C
ONGC electrical engg questions with answers and explanations ONGC previous years sample placement papers with explanations,ONGC sample questions for electrical engg,mechanical engg,civil engg questions with answers
1 The RMS value of the voltage u(t) =3 + 4cos (3t) is
Options
A) Ö (17) V
B) 5 V
C) 7 V
D) (3 + 2 Ö
Correct Answer A
2 The open loop transfer function of a unity feed back control system is given as G(s) = as + 1 s 2 The value of ‘a’ to give a phase margin of 45° is equal to
Options
A) 0.141
B) 0.441
C) 0.841
D) 1.141
Correct Answer C
3 The armature resistance of a permanent magnet dc motor is 0.8 W. At no load, the motor draws 1.5 A from a supply voltage of 25 V and runs at 1500 rpm. The efficiency of the motor while it is operating on load at 1500 rpm drawing a current of 3.5 A from the same source will be
Options
A) 48.0%
B) 57.1%
C) 59.2%
D) 88.8%
Correct Answer A
4 The solution of the first order differential equation x(t) = -3x(t), x (0) = x 0 is
Options
A) x (t) = x 0 e -3t
B) x (t) = x 0 e -3
) x (t) = x 0 e -1/3
D) x (t) = x 0 e -1 )
Correct Answer A
5 The unit impulse response of a second order under-damped system starting from rest is given by c(t) = 12.5 e -6t sin 8 t, t 0 The steady-state value of the unit step response of the system is equal to
Options
A) 0
B) 0.25
C) 0.5
D) 1.0
Correct Answer D
6 A single-phase, 230 V, 50 Hz, 4 pole, capacitor-start induction motor has the following stand-still impedances Main winding Z m = 6.0 + j4.0 W Auxiliary winding Z a = 8.0 + j6.0 W The value of the starting capacitor required to produce 90° phase difference between the currents in the main and auxiliary windings will be
Options
A) 176.84 m F
B) 187.24 m F
C) 265.26 m F
D) 280.86 m F
Correct Answer A
7 A single-phase half-controlled rectifier is driving a separately excited dc motor. The dc motor has a back emf constant of 0.5 V/rpm. The armature current is 5 A without any ripple. The armature resistance is 2 W . The converter is working from a 280 V, single phase ac source with a firing angle of 80°. Under this operating condition, the speed of the motor will be
Options
A) 339 rpm
B) 359 rpm
C) 366 rpm
D) 386 rpm
Correct Answer C
8 The 8085 assembly language instruction that stores the content of H and L registers into the memory locations 2050 H and 2051 H , respectively, is
Options
A) SPHL 2050 H
B) SPHL2051 H
C) SHLD 2050 H
D) STAX 2050 H
Correct Answer C
9 A 50 Hz, 4-pole, 500 MVA, 22 kV turbo-generator is delivering rated megavolt-amperes at 0.8 power factor. Suddenly a fault occurs reducing is electric power output by 40%. Neglect losses and assume constant power input to the shaft. The accelerating torque in the generator in MNm at the time of the fault will be
Options
A) 1.528
B) 1.018
C) 0.848
D) 0.509
) Correct Answer A
10 The Nyquist plot of loop transfer function G(s) H(s) of a closed loop control system passes through the point (-1, j0) in the G(s) H(s) plane. The phase margin of the system is
Options
A) 0°
B) 45°
C) 90°
D) 180°
Correct Answer D
11 A 50 kW dc shunt motor is loaded to draw rated armature current at any given speed. When driven (i) at half the rated speed by armature voltage control and (ii) at 1.5 times the rated speed by field control, the respective output powers delivered by the motor are approximately.
Options
A) 25kW in (i) and 75kW in (ii)
B) 25kW in (i) and 50kW in (ii)
C) 50kW in (i) and 75kW in (ii)
D) 50kW in (i) and 50kW in (ii)
Correct Answer B
12 A hydraulic turbine having rated speed of 250 rpm is connected to a synchronous generator. In order to produce power at 50 Hz, the number of poles required in the generator are
Options
A) 6
B) 12
C) 16
D) 24
Correct Answer D
13 For the equation x(t)+3 x(t) +2x(t) = 5, the solution x (t) approaches which of the following values as t ® ¥ ?
Options
A) 0
B) 5 2
C) 5
D) 10
Correct Answer B
14 The following motor definitely has a permanent magnet rotor
Options
A) DC commutator motor
B) Brushless dc motor
C) Stepper motor
D) Reluctance motor
Correct Answer C
15 A110 kV, single core coaxial, XLPE insulated power cable delivering power at 50Hz, has a capacitance of 125 nF/km. If the dielectric loss tangent of XLPE is 2 x 10 -4 , the dielectric power loss in this cable in W/km is Options
A) 5.0
B) 31.7
C) 37.8
D) 189.0
Correct Answer D
16 The simultaneous application of signals x(t) and y(t) to the horizontal and vertical plates, respectively, of an oscilloscope, produces a vertical figure-of-8 display. If P and Q are constants, and x(t) = P sin (4t + 30), then y(t) is equal to
Options
A) Q sin (4t – 30)
B) Q sin (2t + 15)
C) Q sin (8t + 60)
D) Q sin (4t + 30)
Correct Answer B
17 A 500 MW 3-phase Y-connected synchronous generator has a rated voltage of 21.5 kV at 0.85pf. The line current when operating at full load rated conditions will be
Options
A) 13.43 kA
B) 15.79 kA
C) 23.25 kA
D) 27.36 kA
Correct Answer B
18 Total instantaneous power supplied by a 3-phase ac supply to a balanced R-L load is
Options
A) zero
B) constant
C) pulsating with zero average
D) pulsating with non-zero average
Correct Answer B
19 The equivalent circuit of a transformer has leakage reactances X 1 , X
Options A) X 1 >> X
B) X 1 << X
X 1 » X
D) X 1 » X
Correct Answer D
20 If P and Q are two random events, then the following is TRUE
Options
A) Independence of P and Q implies that probability (P Q ) = 0
B) Probability (P Q ) Probability (P) + Probability (Q)
C) If P and Q are mutually exclusive, then they must be independent
D) Probability (P Q ) Probability (P) Correct Answer D
ONGC civil engineering questions
ONGC civil engineering questions with answers,ONGC graduate trainees job recruitment notification and ONGC slecton procedure,ONGC previous years solved questions with answers
1. A rectangular beam of length I supported at its two ends carries a central concentrated load W at its centre. The maximum deflection occurs
at the ends
at 1/3 from both ends
at the mid span-Answer
at 1/4 from both ends
2. If the depth is kept constant for beam of uniform strength then its width will vary proportional to
M-Answer
Sqrt(M)
M^2
M^3
3. When a beam deflects into a uniform strength then its width will vary proportional to
I/2R
I/8R
I^2 /8R-Answer
I^2 /2d
4. The longitudinal stress in a thin cylindrical shell is
Pd/4t-Answer
Pd/2t
Pt/4d
Pt/2d
5. The ratio of maximum shear stress and average shear stress for a rectangular section is
1.5-Answer
2
2.5
3
6. A fixed beam of span L carries a central point load W. The maximum sagging bending moment in the beam is
WL/2
WL/4-Answer
WL/8
WL/16
7. Air entrainment in the concrete increases
workability
strength-Answer
the effects of temperature
the unit weight
8. The relation between modulus of rupture Fcr and characteristic strength of concrete Fck is given by
Fcr = 0.35 S Fck-Answer
Fcr = 0.5 S Fck
Fcr = 0.7 S Fck
Fcr = 1.2 S Fck
9. The compressive strength of 100 mm cube as compared to 150 mm cube is always
less
more
equal-Answer
may be any of the above
10. For a slab supported on its four edges with corners held down and loaded uniformly, the Marcus correction factor to the moments obtained by Grashoff Rankine’s theory
is always less than 1
is always greater than 1-Answer
can be more than 1
can be less than 1
11. For bars in tension a standard hook has an anchorage value equivalent to a strength length of
8
12
16-Answer
24
12. Cube strength of controlled concrete to be used for pre-tensioned and post-tensioned work respectively should not be less than
350 Kg/cm^2 and 420 Kg/cm^2
420 Kg/cm^2 and 530 Kg/cm^2-Answer
420 Kg/cm^2 and 350 Kg/cm^2
530 Kg/cm^2 and 420 Kg/cm^2
13. The creep strains are
caused due to dead loads only-Answer
caused due to live loads only
caused due to both dead and live load
independent of loads
14. Ratio of compressive strength to tensile strength of concrete
increases with age-Answer
decreases with age
remains constant
15. In limit state design of concrete for flexure, the area of stress block is taken as
0.36 Fck Xu-Answer
0.42 Fck Xu
0.446 Fck Xu
0.53 Fck Xu
16. The fitness modulus of the fine aggregate is in the range of
2.0 to 3.5-Answer
3.5 to 5.0
5.0 to 7.0
6.0 to 8.5
17. According to IS:456-1978, the maximum reinforcement in a column is
2%
4%
6%-Answer
8%
18. The minimum cover in a slab should neither be less than the diameter of bar nor less than
10 mm
15 mm-Answer
20 mm
13 mm
19. If the permissible stress in steel in tension is 140 N/mm^2, Permissible stress in concrete in bending compression is 5N / mm^2. Then the depth of neutral axis for a singly reinforced rectangular balanced section will be
0.35 d
0.40 d-Answer
0.45 d
dependent on grade of concrete also
20. The slab is designed as one way if the ratio of long span to short span is
less than 1
between 1 and 1.5
between 1.5 and 1.2
greater than 2-Answer
21. In any beam when the moment of inertia about the neutral axis is doubled, its deflection is
doubled
tripled
halved-Answer
minimum
22. The limits of percentage of the longitudinal reinforcement in a column is given by
0.15% to 2%
0.8% to 4%
0.8% to 6%-Answer
0.8% to 8%
23. A rigid prop provided for a beam
brings the bending for a beam
brings the deflection at the prop to zero-Answer
brings the slopes at the section to zero
brings the shear force at the section to zero
24. In a simply supported beam AB with a concentrated load W at a distance ‘a’ from support A and ‘b’ from support B, the deflection under the load is
wa^2 b^2 / 3EIL-Answer
wa^2 / 3EI
wa^2 b^2 /3EI
wa^2 b + 2/EIL
25. For the design of retaining walls the minimum factor of safety against over-turning is taken as
1.5
2.0-Answer
2.5
3.0
26. A cantilever beam is loaded by a point load at the free end. It is likely to fail by B.M.
under the load
at mid span
at support-Answer
none
27. The distance between centre lines of a broad gauge is 1.686m. The most economic length of sleeper for efficient distribution of B.M. is
1.866 m
2.866 m-Answer
3.866 m
0.866 m
28. In a simply supported beam of span L carrying an eccentric couple M acting at a distance A from the left support, the reaction included at the support is
M/L-Answer
L/M
ML
1/ML
29. Area of shear force diagram between two sections is
70 KNm
140 KNm-Answer
280 KNm
30. The section modulus of square section of side A is
a^2 /6
a^3 /6-Answer
a^4 /12
a^3 /12
31. The minimum percentage of mild steel reinforcement in walls of RCC water tanks of 450 mm thick is about
0.20-Answer
0.30
0.24
0.16
ONGC electrical engg questions with answers,ONGC technical questions with answers,ONGC previous years solved questions with answers,ONGC EEE,ECE,Civil,Mechanical,engg questions with answers,ONGC free solved sample placement papers with detailed explanations,ONGC technical question papers
ONGC Electrical Engg questions
1. Dielectric strength in case of mica can be expected to be more than
(A) 500 kV/mm-Answer
(B) 1500 kV/mm
(C) 2500 kV/mm
(D) 3500 kV/mm.
2. All of the following dielectric materials are preferred for high frequency applications EXCEPT
(A) Polyethylene
(B) Butyl rubber-Answer
(C) Teflon
(D) Polystyrene.
3. Polar dielectrics are normally used for
(A) high frequencies
(B) microwaves
(C) dc and power frequencies-Answer
(D) none of the above.
4. Which of the following is a polar dielectric ?
(A) Teflon
(B) Quartz
(C) Nylon-Answer
(D) Polyethylene.
5. Which of the following is a non-polar dielectric ?
(A) Polystyrene-Answer
(B) Phenolic plastics
(C) Plasticized cellulose acetate
(D) Castor oil.
6. The impurity in liquid dielectric which has significant effect in reducing the breakdown strength, is
(A) dust
(B) dissolved gases
(C) moisture
(D) ionic impurities.
7. The relationship between the breakdown voltage V and gap d is normally given as
(A) d = kV2
(B) d=kV3
(C) V = kd
(D) v = kdn.-Answer
8. A good dielectric should have all the following properties EXCEPT
(A) high mechanical strength
(B) high resistance to thermal deterioration
(C) high dielectric loss-Answer
(D) freedom from gaseous inclusions.
9. The variety of paper used for insulation purpose is
(A) blotting paper
(B) rice paper
(C) craft paper-Answer
(D) mill-board.
10. Which variety of mica is hard and brittle ?
(A) Muscovite
(B) Phlogopite
(C) Fibiolite
(D) Lipidolite.-Answer
11. Corona effect can be identified by
(A) bushy sparks
(B) faint violet glow-Answer
(C) red light
(D) arcing between conductors and earth.
12. The phenomenon of corona is generally accompanied by
(A) a bang
(B) a hissing sound
(C) magnetic hum
(D) all of the above.
13. Van de Graaff generators are useful for
(A) Very high voltage and low current applications-Answer
(B) Very high voltage and high current applications
(C) Constant high voltage and current applications
(D) High voltage pulses only.
14. In Van de Graaff generators output voltage is controlled by
(A) controlling the corona source voltage-Answer
(B) controlling the belt speed
(C) controlling the lower spray point
(D) any of the above.
15. A Tesla coil is a
(A) cascaded transformer
(B) coreless transformer
(C) high frequency resonant transformer-Answer
(D) low impedance transformer.
16. Switching surge is
(A) high voltage dc
(B) high voltage ac
(C) short duration transient voltage-Answer
(D) hyperbolically dying voltage.
17. Moles bridge is used to measure
(A) properties of dielectric at dc
(B) dispersion in insulation-Answer
(C) high frequency high voltages
(D) modulation ratio frequencies.
18. Insulators for high voltage applications are tested for
(A) power frequency tests
(B) impulse tests
(C) both (A) and (B) above-Answer
(D) none of the above.
19. Impulse testing of transformers is done to determine the ability of
(A) bushings to withstand vibrations
(B) insulation to withstand transient voltages-Answer
(C) windings to withstand voltage fluctuations
(D) all of the above.
20. Transformers contribute to radio interference due to
(A) corona discharges in air
(B) internal or partial discharges in insulation
(C) sparking
(D) any of the above.-Answer
21. As compared to air the relative dielectric strength of sulphur hexafluoride is nearly
(A) 1.5 times
(B) 2.5 times-Answer
(C) 4.0 times
(D) 5.0 times.
22. The electrical breakdown strength of insulating materials depends on
(A) nature of applied voltage
(B) imperfections in dielectric material
(C) pressure, temperature and humidity
(D) all of the above.-Answer
23. Which of the following gas has been used as insulating medium in electrical appliances ?
(A) Nitrogen
(B) Carbon dioxide
(C) Sulphur hexafluoride-Answer
(D) Freon.
24. Vacuum insulation is used in all of the following EXCEPT
(A) Particle accelerators
(B) EHT of color TV-Answer
(C) Field emission tubes
(D) X-rays.
25. Liquids are generally used as insulating materials up to voltage stresses of about
(A) 100 MV/cm
(B) 50 MV/cm
(C) 50 kV/cm-Answer
(D) 500 V/cm.
26. Electro-mechanical breakdown of solid insulating materials occurs due to
(A) magnetic bum
(B) vibrations
(C) mechanical stresses produced by the electrical field-Answer
(D) electrical stresses produced by the voltage fluctuations.
27. Match the following :
(F is force exerted on a charge q in the electric field E and S is the closed surface containing charge q, D is the flux density).
Equation Nomenclature
(a) fs E dS = q / e0 (i) Poisson’s equation
(b) ? .D = ? (ii) Laplace’s equation
(c) ?2 .f = – ?/ e0 (iii) Guass theorem
(d) ?2 .f = 0 (iv) Charge density
(A) a – (i), b – (ii), c – (iii), d – (iv)
(B) a – (ii), b – (i), c – (iv), d – (iii)
(C) a – (iv), b – (i), c – (ii), d – (iii)
(D) a – (iii), b – (iv), c – (i), d – (ii).-Answer
28. Surge voltage originate in power systems due to
(A) lightning
(B) switching operations
(C) faults
(D) any of the above.-Answer
29. All of the following are the preferred properties of a dielectric gas EXCEPT
(A) high dielectric strength
(B) physiological inertness
(C) low atomic number-Answer
(D) good heat transfer.
30. Corona results in
(A) improvement in power factor
(B) increased capacitive reactance of transmission lines
(C) radio interference-Answer
(D) better regulation.
31. Which of the following technique/method is-used for the measurements of ac high frequency voltages ?
(A) Peak voltmeter-Answer
(B) Series resistance micro ammeter
(C) Resistance potential divider
(D) Any of the above.
32. Which of the following method or technique can be used for the measurement of high dc voltages ?
(A) Generating voltmeter-Answer
(B) Electrostatic voltmeter
(C) Peak voltmeter
(D) Any of the above.
33. All of the following methods/techniques can be used for the measurement of high ac voltages EXCEPT
(A) Potential dividers
(B) Potential transformers
(C) Electrostatic voltmeters
(D) Half effect generators.-Answer
34. Surge diverters are
(A) non-linear resistors in series with spark gaps which act as fast switches-Answer
(B) arc quenching devices
(C) shunt reactors to limit the voltage rise due to Ferranti effect
(D) over-voltages of power frequency harmonics.
35. Impulse voltages are characterized by
(A) polarity
(B) peak value
(C) time of half the peak value
(D) all of the above.-Answer
36. Paschen’s law is associated with
(A) breakdown voltage-Answer
(B) ionization
(C) thermal radiations
(D) none of the above.
37. The essential condition for the Paschen’s law to be valid is that
(A) voltage must be dc
(B) voltage must be ac
(C) temperature must be constant-Answer
(D) humidity must be low.
38. The breakdown voltage in gases depends on
(A) distance between the electrodes
(B) relative air density
(C) humidity
(D) all of the above.-Answer
39. At unvarying temperature breakdown voltage in a uniform field is a function of the product of gas pressure and distance between the electrodes. The above statement is known as
(A) Electron avalanche
(B) Thermal stability principle
(C) Paschen’s law-Answer
(D) Breakdown voltage law.
40. Large capacity generators are manufactured to generate power at
(A) 440 V
(B) 6.3 to 10.5 kV-Answer
(C) 132 kV to 220 kV
(D) 400 kV.
41. Which soil has the least specific resistance ?
(A) Land
(B) Loamy soil
(C) Clay
(D) Peat.-Answer
42. Which soil has the maximum specific resistance ?
(A) Black cotton soil
(B) Sand-Answer
(C) Peat
(D) Loamy soil.
43. In sphere gaps, the sphere are made of
(A) aluminium
(B) brass
(C) bronze
(D) any of the above.-Answer
44. In ‘plasma’ state a gas
(A) loses electrical conductivity
(B) conducts electricity-Answer
(C) becomes perfect insulator
(D) attracts moisture.
45. Which of the following statement about corona is incorrect ?
(A) Corona gives rise to radio interference
(B) Corona results in loss of power in transmission
(C) Corona discharge can be observed as red luminescence-Answer
(D) Corona is always accompanied by a hissing noise.
46. The property of a coil due to which it opposes the change of current flowing through itself is called of the coil.
(a) Static inductance
(b) Dynamic inductance
(c) Self inductance
(d) Mutual inductance
Ans : c
47. is used to sense the flow of current in a electric circuit.
(a) Ammeter
(b) Voltmeter
(c) Wattmeter
(d) Galvanometer
Ans : d
48. The phenomenon of the self induction is felt only when the current in the coil is
(a) Changing
(b) Increasing
(c) Decreasing
(d) All the above
Ans :d
49. The negative sign in the induced emf of self induction indicates that energy is being absorbed from the electric circuit and stored as _______ energy in the coil.
(a) mechanical
(b) Electronic
(c) electric
(d) Magnetic
Ans :d
50. Unit of co-efficient of self induction of the circuit is
(a) ) Volt
(b) Ampere
(c) Henry
(d) Linkages
Ans : c
51. Unit of induced emf is
(a) ) Volt
(b) Ampere
(c) Henry
(d) Linkages
Ans :a
52. The property of one coil due to which it opposes the change in the other coil is called…………. between two coils.
(a) Dynamic inductance
(b) Static inductance
(c) Self inductance
(d) Mutual inductance
Ans : d
53. The unit of mutual inductance is
(a) Volt
(b) Ampere/ Volt
(c) Henry
(d) Linkages
Ans : c
13. In the expression e
= M dI / dt , M represents
(a) Mutual induction
(b) Mutual inductance
(c) Number of lines of force
(d) None of these
Ans : b
54. If 0.75 V is induced emf and resistance offered by the coil is 200 ohm then induced current is
(a) 3.75 A
(b) 3. 75 mA
(c) 3. 75 micro Ampere
(d) 37.5 mA
Ans : b
55. If magnetic flux changes from 0.8 Wb to 0.3 Wb, then change in flux is______ Wb.
(a) 1.1
(b) 0.5
(c) -0.5
(d) -1.1
Ans : c
56. If Number of turns of coil is 200 and if the current is 1 amps, then MMF is ________
(a) 2000 AT
(b) 200 AT
(c) 20 AT
(d) 0.5 AT
Ans : b
57. Leakage factor can be called as
(a) Fringing
(b) Coefficient of inductance
(c) Magneticcoefficient
(d) Hopkinson’s coefficient
Ans : d
58. Movement of electrons are called as
(a) MMF
(b) Current
(c) Voltage
(d) Flux
Ans : b
59. Flux density is equal to ________ of flux and area of cross – section.
( a) Sum
(b) Difference
(c) Product
(d) Fraction
Ans : d
60. NI expression is called
(a) MMF
(b) EMF
(c) Flux linkage
(d) Magnetic intensity
Ans : a
61. Expression NI/L is called
(a) MMF
(b) EMF
(c) Flux linkage
(d) Magnetic intensity
Ans :d
62. Expression for mutual inductance is
(a) –L dI/dt
(b) MdIdt
(c) N2 f / 2/ I
(d) Nf/I 1
Ans : b
63. Faraday’s law of electromagnetic induction is e=
( a ) –Nd f/dt
(b ) MdIdt
(c ) N2 f / 2/ I
(d) Nf/I Ans : a
64. The constant K in case of mutual induction is equal to
(a)f1/f
(b) f2/f
(c)f1/I
(d) f2/I
Ans : b
65. Product of the permeability µ0µis equal to
(a) Magnetic flux
(b) Magnetic field
(c) Magnetic intensity
(d) Magnetic field / magnetic intensity
Ans : d
66. Expression for self induced emf is
(a) –L dI/dt
(b) MdI
(c) N
Ans : a
67. is normally termed as flux linkages.
68. The term Nf/I is generally called as .
(a) Self inductance
(b) Mutual inductance
(c) Flux linkage
(d) Induced emf
Ans : a
69 In the expression for reluctance S = L/µA of a conduced, letter A represents_________ of the conductor.
(a) Total area
(b) Surface area
(c) Cross- sectional area
(d) None of these.
Ans : c
ONGC chemical engg questions with answers, ONGC previous years technical questions with answers, ONGC latest free solved sample placement papers. ONGC aptitude,reasoning,technical questions with answers
ONGC Chemical Engineering questions with answers
1. Dissolving salt in water is an example of which type of change ?
Physical-Answer
Nuclear
Chemical
Biochemical
2. When nuclear change takes place, which is true
Energy is destroyed
Energy is released-Answer
Energy is changed
None of these
3. Which type of radiation is unaffected by magnetism ?
Alpha
Beta
Gamma-Answer
All of these
4. Which temperature scale is an absolute scale, where the zero point is the lowest possible temperature ?
Kelvin-Answer
Celsius
Fahrenheit
Centigrade
5. The relative randomness of molecules in the states of matter is best indicated by
Solid > Liquids > Gas-Answer
Liquid > Gas > Solid
Liquid > Solid > Gas
Gas > Liquid > Solid
6. Whether or not two liquids are miscible is determined by
Molecular Size : Molecules of similar sizes tend to mix together
Density : Liquids of simliar densities usually mix well together
Polarity : Polar and nonpolar liquids are not miscible while polar liquids can usually be mixed with each other-Answer
All of the above factors directly affect miscibility
7. The Triple Point is
The combination of standard temperature, pressure and volume
The combination of temperature and pressure at which the solid, liquid and gas phases can coexist at equilibrium
The combination of pressure and temperature at which liquid, gas, and plasma phases all exist in equilibrium-Answer
The combination of temperature and pressure at which liquids and gases cannot be distinguished from each other
8. If the work done by a force depends only on the initial and final stages and not on the path taken, then this type of force will be
Conservative Force-Answer
Non-conservative Force
Conservative as well as Non-conservative force
None of these
9. Working between which pair of following temperatures, the efficiency of a carnot engine will be maximum ?
10 Degrees F and 10 Degress R-Answer
10 Degrees F and 10 Degress C
10 Degrees R and 10 Degress C
It will be same in all the above cases
10. Dacron is a
Polyester-Answer
Polyamide
Nylon
Resin
11. Which of the following has the highest stable atom ?
Bi
Al
Cl
Pb-Answer
12. In Friedel-Crafts reaction, AlCl3 acts as a
Lewis Acid-Answer
Lewis Base
Catalyst
Reactant
13. The number of unpaired electrons in [Ni(CO)4] is
Zero-Answer
One
Three
Five
14. Iodoethane reacts with sodium to form
Pentane
Propane
Butene
Butane-Answer
15. An ideal gas has maximum density at
1 atm, 300 K
2 atm, 150 K-Answer
0.5 atm, 600 K
1 atm, 500 K
16. Which of the following metals is present in brass, bronze and german silver ?
Defence Mechanism
Hydrolysis of ATP
Trifling of Contraction-Answer
Generating right electrical potential across cell membrane
17. First ionization potential is ___________ second ionization potential.
Less than-Answer
More than
Equal to
None of these
18. n-propyl benzene is best prepared by
Friedel-Crafts Reaction
Wurtz Reaction
Wurtz-Fitting Reaction-Answer
Grignard Reaction
19. Chloroform is slowly oxidized by air to
Formly Chloride
Carbonyl Chloride-Answer
Trichloroacetic Acid
Formic Acide
20. Electrophoresis is
Movement of colloidal particle under the influence of electric field-Answer
Movement of colloidal particle under the influence of magnetic field
Movement of colloidal particle in zig-zag fashion
Scattering of light by colloidal particles
21. Rosenmund’s reduction of an acyl chloride gives
Alcohol
Ester
Hydrocarbon
Aldehyde-Answer
22. Pyrophosphoric acid is
Monobasic
Dibasic-Answer
Tribasic
Basic
23. Which of the following is an example of a mathematical model ?
Area of a circle = PI x Radius^2
Volume of a cube = Length^3
Force = Mass x Acceleration
All of the above-Answer
24. The specific activity of an enzyme is relatively constant between pH 3-8. If the enzyme activity at pH 7.0 is to be modeled, which of the following would be a reasonable simplifying assumption ?
Specific activity is not dependent on temperature
Specific activity is not dependent on substrate concentration
Specific activity is not dependent on pH-Answer
All of the above
25. The bioreactor which is most commonly used in industry is the
Batch Fermenter
Fed Batch Fermenter-Answer
Continous Fermenter
Batch Continous Fermenter
26. Which of the following is correct with regards to microbial growth ?
Cells are autocatalysts and thus the rate of increase in biomass (dX/dt) keeps changing
Many factors affect cell growth
The rate of increase in biomass concentration is not constant during a fermentation
All of the above are correct-Answer
27. During a batch fermentation, when would the specific growth rate be lowest ?
During exponential phase
During the lag and stationary phase-Answer
When cells are growing at their fastest rate
Throughout the fermentation
28. Which of the following describes a limitation of the exponential growth model ?
Biomass growth is assumed to be not linked to the availability of nutrients or substrates
It does not predict when cell growth will cease
It predicts that all types of cells under all conditions will grow exponentially
All of the above are correct-Answer
29. In large scale bioreactors, dissolved oxygen levels are often so low that they restrict the rate of cell growth. In this case
Dissolved oxygen would be the growth limiting nutrient
The nitrogen source would be the growth limiting nutrient
The carbon source would be the growth limiting nutrient-Answer
Dissolved oxygen levels would not be the growth limiting nutrient
30. Which of the following is not correct ?
The Monod model is an empirical correlation
The Michaelis Menten model is a mechanistic model
The Monod model was derived from a study of the mechanism of microbial growth-Answer
The Michaelis Menten model was derived from a study of the mechanism of enzyme action
31. The technique of Nick Translation was developed by
Rigby and Paul Berg-Answer
Winkler
Roderick and Rigby
None of them
32. Which technique allows knowing the status in the interphase ?
Hybridization Microarray
Karyotyping
Fluorescence in situ Hybridization-Answer
Pedigree Analysis
33. _________ observed that protein sequences undergo variation during evolution according to certain patterns
Zuckerkandl
Pauling
Margaret Dayoff-Answer
All of them
34. Which of the following would have the highest oxygen transfer rate characteristics ?
A sparged stirred tank bioreactor being stirred at 200 rpm
A non-sparged stirred tank bioreactor being stirred at 200 rpm
A shake flask being mixed at 200 rpm
All of the above would have equivalent oxygen transfer rate characteristics
The answer is A sparged stirred tank bioreactor being stirred at 200 rpm
35. Molar heat capacity of water in equilibrium with ice at constant pressure is
Zero
Infinity
40.45 KJ K^-1 mol^-1
75.48 JK^-1 mol^-1
The answer is Zero
36. Ammonium molybdate test is used to detect the presence of
Borate
Phosphate
Chloride
Bromide
The answer is Phosphate
37. Increasing the temperature of an aqueous solution will cause
Decrease in Molality
Decrease in Molarity
Decrease in Mole Fraction
Decrease in Percentage by Weight
The answer is Decrease in Molarity
38. IUPAC name of the compound CH3CH(OH)COOH is
Lactic Acid
A-Hydroxypropanoic Acid
Carboxy Propanol
2-Hydroxypropanoic acid
The answer is 2-Hydroxypropanoic acid
39 Which of the following will not displace hydrogen ?
Ba
Pb
Ag
Sn
The answer is Ag
40. The amount of heat measure for a reaction in a bomb calorimeter is
DG
DH
DE
PDV
The answer is DE
41. Which of the following oxides is most amphoteric ?
Na2O
Al2O3
SO3
P2O5
The answer is Al2O3
42. Which among the following is most basic compound ?
Benzylamine
Aniline
Acetanilide
P-Nitroaniline
The answer is Benzylamine
43. Which of the following elements form interstitial compounds ?
Fe
Co
Ni
All of these
The answer is All of these
44 The EAN of Co in K3[Co(NH3)6] is
34
35
36
37
The answer is 36
45 The position of electron is identified by quantum numbers n and l. (i) n = 4, l = 1 (ii) n = 4, l = 0 (iii) n = 3, l = 2 (iv) n = 3, l = 1 The order of increasing energy from the lowest to highest is
(iv) < (ii) < (iii) < (i)
(ii) < (iv) < (i) < (iii)
(i) < (iii) < (ii) < (iv)
(iii) < (i) < (iv) < (ii)
The answer is (iv) < (ii) < (iii) < (i)
46. Gutta Percha is
Trans-polyisoproprene
A synthetic polymer
A very hard material
All are correct
The answer is All are correct
47. Which one of following does not give acetylene with water ?
CaC2
BaC2
SrC2
Al4C3
The answer is Al4C3
48. Normality of 0.3 M phosphoric acid (H3PO3) is
0.3
0.6
0.9
0.1
The answer is 0.6
49. ___________ technique is based on the fact that there are variations in the DNA sequence of restriction sites among different individuals and different species.
Polymer Chain Reaction
Hybridoma
Restriction Fragment Length Polymorphism
None of these
The answer is Restriction Fragment Length Polymorphism
50 Which enzyme forms phosphodiester bonds between adjacent nucleotides and covalently links two individual fragments of double stranded DNA
Alkaline Phosphates
DNA Polymerase
DNA Liqase
Exonuclease
The answer is DNA Liqase
51 Name the enzyme used to prevent unwanted self-liquation of vector DNA molecules in cleaning procedures
Alkaline Phosphates
DNA Ligase
DNA Polymerase
Helicases
The answer is Alkaline Phosphates
52. Many of the vector for use in eukaryotic cells are constructed such that they can exist in both the eukaryotic cell and E.coli. Such vectors are known as
Shuttle Passengers
Shuttle Vectors
Expression Vectors
All of these
The answer is Shuttle Vectors
53 ___________ are constructed by combining certain features of plasmid and the cos sites of the phage lambda
Hybrides
Cybrids
Cosmids
None of these
The answer is Cosmids
54 ____________ are used as vector to clone DNA fragments of more than 1 Mb in size
Yeast Artificial Chromosomes
Bacterial Artificial Chromosomes
Plant Chromosomes
All of these
The answer is Yeast Artificial Chromosomes
55 ___________ vector can accommodate upto 300-350 kb of foreign DNA
YAC
BAC
Plant
Animal
Answer BAC
56 A collection of clones representing the complete genome of an organism is called
Genomic Library
DNA Library
Inventory
None of these
Answer-Genomic Library
57. Which method is used to introduce recombinant DNA into host cell ?
Electroporation
Microinjection
Biolistics
All of the above-Answer
58. Who invented Polymerase Chain Reaction ?
Ely Lilly
Kary Mullis
Sanger
All of these
The answer is Kary Mullis
59 Who developed Dideoxynucleotide Chain termination method ?
Frederick Sanger and Andrew Coulson
Andrew Coulson and Maxam
Gilbert
All of them
The answer is Frederick Sanger and Andrew Coulson
60 Who coined the term genomics ?
Winkler
Thomas Roderick
Craig Venter
All of them
The answer is Thomas Roderick
61. ___________ primarily involves high-throughput DNA sequencing followed by assembly, organization and management of DNA sequence
Structural Genomics
Functional Genomics
Contigs
None of these
The answer is Structural Genomics
62. ____________ deals with the reconstruction of the genome to determine the biological function of genes and gene interaction
Structural Genomics
Functional Genomics
Random Libraries
Contigs
The answer is Functional Genomics
63 _________ of genomic DNA are constructed in small and edium seat plasmid vector along with genomic shotgun large unseat BAC library
Random Arrays
Mirco Arrays
Random Libraries
All of these
The answer is Random Libraries
64. BLAST means
Basic Local Alignment Search Tool
Basic Local Array Search Tool
Basic Linkage Alignment Search Technique
None of them
The answer is Basic Local Alignment Search Tool
65. ___________ is a closed culture system, which contains limited amount of nutrients
Fed-Batch Culture
Continuous Culture
Batch Culture
All of these
The answer is Batch Culture
66.If a batch culture is continuously or sequentially fed with fresh medium without remaining the growing culture, it is called
Batch Culture
Fed-Batch Culture
Continuous Culture
Another Culture
The answer is Fed-Batch Culture
67 If the temperature of saturated water is increased infinitesimally at constant entropy, the resulting state of water will be
(A) Liquid
(B) Liquid – vapor coexistence
(C) Saturated vapor
(D) Solid
68 Water is flowing under laminar conditions in a pipe of length L . If the diameter of the pipe is
doubled, for a constant volumetric flow rate, the pressure drop across the pipe
(A) decreases 2 times
(B) decreases 16 times
(C) increases 2 times
(D) increases 16 times
70 For uniform laminar flow (in the x -direction) past a flat plate at high Reynolds number, the local boundary layer thickness (? ) varies with the distance along the plate ( x ) as
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Mechanical, Electrical, E &T, Instrumentation , Civil, Transport, Finance, HR, Materials Management, Medical & Security. previous years questions with answers,ONGC Free solved sample placement papers
TYPICAL QUESTIONS & ANSWERS OBJECTIVE TYPE QUESTIONS
Q.1 The two windings of a transformer is
(A) conductively linked.
(B) inductively linked.
(C) not linked at all.
(D) electrically linked.
Ans : B
Q.2 A salient pole synchronous motor is running at no load. Its field current is switched off.vThe motor will
(A) come to stop.
(B) continue to run at synchronous speed.
(C) continue to run at a speed slightly more than the synchronous speed.
(D) continue to run at a speed slightly less than the synchronous speed.
Ans: B
Q.3 The d.c. series motor should always be started with load because
(A) at no load, it will rotate at dangerously high speed.
(B) it will fail to start.
(C) it will not develop high starting torque.
(D) all are true.
Ans: A
Q.4 The frequency of the rotor current in a 3 phase 50 Hz, 4 pole induction motor at fullvload speed is about
(A) 50 Hz.
(B) 20 Hz.
(C) 2 Hz.
(D) Zero.
Ans: C
Q.5 In a stepper motor the angular displacement
(A) can be precisely controlled.
(B) it cannot be readily interfaced with micro computer based controller.
(C) the angular displacement cannot be precisely controlled.
(D) it cannot be used for positioning of work tables and tools in NC machines.
Ans: A
Q.6 The power factor of a squirrel cage induction motor is
(A) low at light load only.
(B) low at heavy load only.
(C) low at light and heavy load both.
(D) low at rated load only.
Ans: A
Q.7 The generation voltage is usually
(A) between 11 KV and 33 KV.
(B) between 132 KV and 400 KV.
(C) between 400 KV and 700 KV.
(D) None of the above.
Ans: A
Q.8 When a synchronous motor is running at synchronous speed, the damper winding produces
(A) damping torque.
(B) eddy current torque.
(C) torque aiding the developed torque.
(D) no torque.
Ans: D
Q.9 If a transformer primary is energised from a square wave voltage source, its output voltage will be
(A) A square wave.
(B) A sine wave.
(C) A triangular wave.
(D) A pulse wave.
Ans: A
Q.9 If a transformer primary is energised from a square wave voltage source, its output voltage will be
(A) A square wave.
(B) A sine wave.
(C) A triangular wave.
(D) A pulse wave.
Ans: A
Q.10 In a d.c. series motor the electromagnetic torque developed is proportional to
(A) Ia .
(B) 1 2/a
(C)I/a1
Ans: B
Q.11 In a 3 – phase induction motor running at slip ‘s’ the mechanical power developed in terms of air gap power Pg is
(A) (s -1 ) Pg .
(B) Pg/(1- s)
(C) (1- s ) Pg .
(D) s × Pg .
Ans: C
Q.12 In a 3 – phase induction motor the maximum torque
(A) is proportional to rotor resistance r2 .
(B) does not depend on r2 .
(C) is proportional to root of r2 .
(D) is proportional to r2/2
Ans: B
Q.13 In a d.c. machine, the armature mmf is
(A) stationary w.r.t. armature.
(B) rotating w.r.t. field.
(C) stationary w.r.t. field.
(D) rotating w.r.t. brushes.
Ans: C
Q.14 In a transformer the voltage regulation will be zero when it operates at
(A) unity p.f.
(B) leading p.f.
(C) lagging p.f.
D) zero p.f. leading.
Ans: B
Q.15 The maximum power in cylindrical and salient pole machines is obtained respectively at load angles of
Ans: 90 degree<90 degree
Q.16 The primary winding of a 220/6 V, 50 Hz transformer is energised from 110 V, 60 Hz supply. The secondary output voltage will be
(A) 3.6 V.
(B) 2.5 V.
(C) 3.0 V.
(D) 6.0 V.
Ans: C
Q.17 The emf induced in the primary of a transformer
(A) is in phase with the flux.
(B) lags behind the flux by 90 degree.
(C) leads the flux by 90 degree.
(D) is in phase opposition to that of flux.
Ans: C
Q.18 The relative speed between the magnetic fields of stator and rotor under steady state operation is zero for a
(A) dc machine.
(B) 3 phase induction machine.
(C) synchronous machine.
(D) single phase induction machine.
Ans: all options are correct
Q.19 The current from the stator of an alternator is taken out to the external load circuit through
(A) slip rings.
(B) commutator segments.
(C) solid connections.
(D) carbon brushes.
Ans: C
Q.20 A motor which can conveniently be operated at lagging as well as leading power factors is the
(A) squirrel cage induction motor.
(B) wound rotor induction motor.
(C) synchronous motor.
(D) DC shunt motor.
Ans: C
Q.21 A hysteresis motor
(A) is not a self-starting motor.
(B) is a constant speed motor.
(C) needs dc excitation.
(D) can not be run in reverse speed.
Ans: B
Q.22 The most suitable servomotor for low power applications is
(A) a dc series motor.
(B) a dc shunt motor.
(C) an ac two-phase induction motor.
(D) an ac series motor.
Ans: B
Q.23 The size of a conductor used in power cables depends on the
(A) operating voltage.
(B) power factor.
(C) current to be carried.
(D) type of insulation used.
Ans: C
Q.24 Out of the following methods of heating the one which is independent of supply frequency is
(A) electric arc heating
(B) induction heating
(C) electric resistance heating
(D) dielectric heating
Ans: C
Q.25 A two-winding single phase transformer has a voltage regulation of 4.5% at full-loadand unity power-factor. At full-load and 0.80 power-factor lagging load the voltage
regulation will be
(A) 4.5%.
(B) less than 4.5%.
(C) more than 4.5%.
(D) 4.5% or more than 4.5%.
Ans: C
% R = Vr cos F + Vx sin F = Vr
p.f = cos F =1 \ F =00
\ kVA = kW & kVAR =0
No reactive power component
Percentage regulation (%R) = Vr cos F ± Vx sin F
When cos F = 0.8 lagging
%R = Vr cos F + Vx sin F
= Vr (0.8) + Vx (0.6)
%R = (0.8)Vr +(0.6) Vx at p.f 0.8 lagging
and %R = Vr at unity p.f
Q.26 In a dc shunt motor the terminal voltage is halved while the torque is kept constant. The resulting approximate variation in speed ‘w’ and armature current ‘ Ia ‘ will be
(A) Both w and Ia are doubled.
(B) w is constant and Ia is doubled.
(C) w is doubled while Ia is halved.
(D) w is constant but Ia is halved.
Ans: B
N V – IaR or N Eb
T Ia F , F Ia
\ T Ia
Q.27 A balanced three-phase, 50 Hz voltage is applied to a 3 phase, 4 pole, inductionmotor. When the motor is delivering rated output, the slip is found to be 0.05. The
speed of the rotor m.m.f. relative to the rotor structure is
(A) 1500 r.p.m.
(B) 1425 r.p.m.
(C) 25 r.p.m.
(D) 75 r.p.m.
Ans: D
NS = 120f /P = 120 x 50 /4 =1500rpm
N = NS ( 1-s) = 1500 (1-0.05) = 1425
\relative speed = 1500 – 1425 = 75 rpm
Q.28 An alternator is delivering rated current at rated voltage and 0.8 power-factor laggingcase. If it is required to deliver rated current at rated voltage and 0.8 power-factor
leading, the required excitation will be
(A) less.
(B) more.
(C) more or less.
(D) the same.
Ans: B
Over excitation gives leading power factor and under excitation gives lagging p.f .
Q.29 A ceiling fan uses
(A) split-phase motor.
(B) capacitor start and capacitor run motor.
(C) universal motor.
(D) capacitor start motor.
Ans: DTo give starting torque and to maintain speed.
Q.30 A stepper motor is
(A) a dc motor.
(B) a single-phase ac motor.
(C) a multi-phase motor.
(D) a two phase motor.
Ans: D
Stepper motor works on 1-phase-ON or 2-phase –ON modes of operation
Q.31 The ‘sheath’ is used in cable to
(A) provide strength to the cable.
(B) provide proper insulation.
(C) prevent the moisture from entering the cable.
(D) avoid chances of rust on strands.
Ans: A
The sheath in underground cable is provided to give mechanical strength.
Q.32 The drive motor used in a mixer-grinder is a
(A) dc motor.
(B) induction motor.
(C) synchronous motor.
(D) universal motor.
Ans: D
The universal motor is suitable for AC & DC both supply systems.
Q.33 A 1:5 step-up transformer has 120V across the primary and 600 ohms resistance
across the secondary. Assuming 100% efficiency, the primary current equals
(A) 0.2 Amp.
(B) 5 Amps.
(C) 10 Amps.
(D) 20 Amps.
Ans: A
I1= V1 /R1 = 120/600 = 0.2 (h = 100%, losses are zero \V1 = VR = I1R1)
Q.34 A dc shunt generator has a speed of 800 rpm when delivering 20 A to the load at theterminal voltage of 220V. If the same machine is run as a motor it takes a line
current of 20A from 220V supply. The speed of the machine as a motor will be
(A) 800 rpm.
(B) more than 800 rpm.
(C) less than 800 rpm.
(D) both higher or lower than 800 rpm.
Ans: C
Ng= Eg (60A / Fpz) Eg = V + Ia Ra ; in generator
Nm= Eb (60A / Fpz) Eb = V – Ia Ra ; in motor
Eg > E b for same terminal voltage
Therefore, Ng > N m
Q.35 A 50 Hz, 3-phase induction motor has a full load speed of 1440 r.p.m. The number ofpoles of the motor are
(A) 4.
(B) 6.
(C) 12.
(D) 8.
Ans: A
N= Ns (1-S) = NS –NS x S
1440 = Ns (1-S)
Ns = 1440 / (1-S)
Ns = (120 f/ p) = 120 x 50/p = 6000 p
Ns will be closer to N i.e 1440
When P=2 ; Ns = 3000 rpm , not close to N
When P=4 ; Ns = 1500 rpm , it is closer to N
Therefore P =4 for N=1440
Q. 36 In a 3-phase synchronous motor
(A) the speed of stator MMF is always more than that of rotor MMF.
(B) the speed of stator MMF is always less than that of rotor MMF.
(C) the speed of stator MMF is synchronous speed while that of rotor MMF is zero.
(D) rotor and stator MMF are stationary with respect to each other.
Ans: D
Because, Motor is magnetically locked into position with stator, the rotor poles areengaged with stator poles and both run synchronously in same direction Therefore,
rotor & stator mmf are stationary w.r.t each other.
Q.37 In a capacitor start single-phase induction motor, the capacitor is connected
(A) in series with main winding.
(B) in series with auxiliary winding.
(C) in series with both the windings.
(D) in parallel with auxiliary winding.
Ans: B
To make single phase motor self start. We split the phases at 90 degree. Hence, motorbehaves like a two phase motor.
Q.38 A synchro has
(A) a 3-phase winding on rotor and a single-phase winding on stator.
(B) a 3-phase winding on stator and a commutator winding on rotor.
(C) a 3-phase winding on stator and a single-phase winding on rotor.
(D) a single-phase winding on stator and a commutator winding on rotor.
Ans: C
Synchros : The basic synchro unit called a synchro transmitter. It’s constructionsimilar to that of a Three phase alternator.
Q.39 As the voltage of transmission increases, the volume of conductor
(A) increases.
(B) does not change.
(C) decreases.
(D) increases proportionately.
Ans: C
Decreases due to skin effect.
Q.40 The size of the feeder is determined primarily by
(A) the current it is required to carry.
(B) the percent variation of voltage in the feeder.
(C) the voltage across the feeder.
(D) the distance of transmission.
Ans: A
Size of conductor depends upon amount of current flow.
Q. 41 The boundary of the protective zone is determined by the
(A) Location of CT
(B) sensitivity of relay used
(C) Location of PT
(D) None of these
Ans: B
The boundary of the protective zone is determined by the sensitivity of relay used. Ifthe relay is more sensitive, the protective zone will be increased.
Q.42 In a three phase transformer, if the primary side is connected in star and secondaryside is connected in delta, what is the angle difference between phase voltage in the
two cases.
(A) delta side lags by -30°.
(B) star side lags by -30°.
(C) delta side leads by 30°.
(D) star side leads by -30°.
Ans: C
This is vector group and has +30° displacement. Therefore, delta side leads by +30°.
Q.43 To achieve low PT error, the burden value should be ____________.
(A) low
(B) high
(C) medium
(D) none of the above
Ans: A In a Potential transformer, burden should be in permissible range to maintain errorlessmeasurement.
Q.44 Slip of the induction machine is 0.02 and the stator supply frequency is 50 Hz.What will be the frequency of the rotor induced emf?
(A) 10 Hz.
(B) 50 Hz.
(C) 1 Hz.
(D) 2500 Hz.
Ans: C
Given : s = 0.02 ; f = 50 Hz
Therefore, frequency of rotor induced emf = s f
= 0.02 x 50 = 1.0 Hz
Q.45 A 4 pole lap wound dc shunt motor rotates at the speed of 1500 rpm, has a flux of 0.4mWb and the total number of conductors are 1000. What is the value of emf?
(A) 100 Volts.
(B) 0.1 Volts.
(C) 1 Volts.
(D) 10 Volts.
Ans: D
Given N = 1500 rpm, F = 0.4 mWb, Z = 1000, P = 4, & A= 4
Therefore, Eb = NFPZ / 60 A
= 1500 x 0.4 x 4 x 1000 x 10-3 / 60 x 4
= 60/6 = 10 volts
Q.46 The synchronous reactance of the synchronous machine is ______________.
(A) Ratio between open circuit voltage and short circuit current at constant field current
(B) Ratio between short circuit voltage and open circuit current at constant field current
(C) Ratio between open circuit voltage and short circuit current at different field current
(D) Ratio between short circuit voltage and open circuit current at different field current
Ans. A
The Synchronous reactance of a synchronous machine is a total steady state reactance,
presented to applied voltage, when rotor is running synchronously without excitation.
Therefore , XS = Ef / IS
= Emf of OC for same If / short circuit current
Q.47 A 3 stack stepper motor with 12 numbers of rotor teeth has a step angle of____________.
(A) 12°
(B) 8°
(C) 24°
(D) 10°
Ans. D
Given m = 3, Nr = 12
Step angle = 360 / m x Nr = 360 /3 x 12 = 10°
Q.48 In case of a universal motor, torque pulsation is minimized by _________.
(A) load inertia
(B) rotor inertia
(C) both rotor and load inertia
(D) none of the above
Ans: C
In a universal motor, torque pulsation is minimized by rotor and load inertia.
Q.49 Oil-filled cable has a working stress of __________ kV/mm
(A) 10
(B) 12
(C) 13
(D) 15
Ans: D
This is defined by dielectric strength of mineral oil i.e. 15 kV/mm.
Q.50 Inverse definite minimum time lag relay is also called ___________
(A) pilot relay.
(B) differential relay.
(C) over current relay.
(D) directional overcurrent relay.
Ans: B
Inverse definite minimum time lag relay characteristic is inverse but minimum time is
fixed. The operating time is inversely proportional to the magnitude of actuating
quantity.
Q.51 Specific heat of nickel –chrome is _____________
(A) 0.112
(B) 0.106.
(C) 0.108.
(D) 0.110.
Ans: None of these
Specific heat of Nickel-Chrome is 440 J/kg°C to 450 J/kg°C
Q.52 The polarity test is not necessary for the single-phase transformer shown in Fig. 1
so as to correctly determine _____________of the transformer.figure
(A) shunt branch parameters.
(B) transformation ratio.
(C) series parameters.
(D) any of the above characteristics.
Ans: D
Polarity test is required for parallel operation of transformers to know the direction of
current flow in secondary circuit w.r.t primary circuit.
Q.53 The short-circuit ratio of a typical synchronous machine is obtained from the OCCand SCC curves of Fig.2 as
As shown in SCC curve the ratio of two field currents
Q.54 The speed-torque characteristics of a DC series motor are approximately similar to
those of the _________motor.
(A) universal
(B) synchronous
(C) DC shunt
(D) two-phase
Ans: A
Universal motor has same characteristics as DC series motor and also known as an a.c
series motor.
Q. 55 The rotor frequency for a 3 phase 1000 RPM 6 pole induction motor with a slip of
0.04 is________Hz
(A) 8
(B) 4
(C) 6
(D) 2
Ans: D
Given: N=1000 rpm ; P= 6; s= 0.04;
and f = NP/ 120
= 10006/120
= 50 Hz
Rotor frequency fr=sf = 0.0450
= 2.0 Hz
Q.56 The torque-speed characteristics of an a.c. operated universal motor has a
______characteristic and it______ be started under no-load condition.
(A) inverse, can
(B) nearly inverse, can
(C) inverse, cannot
(D) nearly inverse, cannot
Ans: C
If torque is zero then speed may exceed up to infinite, that is dangerous for machine
and machine can be damaged.
N 1/ T
Q.57 In the heating process of the ________type a simple method of temperature control is
possible by means of a special alloy which loses its magnetic properties at a particular
high temperature and regains them when cooled to a temperature below this value.
(A) Indirect induction over
(B) core type induction furnace
(C) coreless induction furnace
(D) high frequency eddy current
Ans: D
Magnetic property of alloy changes with change of the temperature and
Heat is produced due to eddy current = i2R and i f2
Q.58 In order to reduce the harmful effects of harmonics on the A.C. side of a high voltage
D.C. transmission system ______are provided.
(A) synchronous condensers
(B) shunt capacitors
(C) shunt filters
(D) static compensators
Ans: C
Xc= 1/?c
Q.59 An a.c. tachometer is just a ________with one phase excited from the carrier
frequency.
(A) two-phase A.C. servomotor
(B) two-phase induction motor
(C) A.C. operated universal motor
(D) hybrid stepper motor.
Ans: D
This is a special purpose machine whose stator coil can be energized by electronically
switched current.
Q.60 The torque, in a _____________is proportional to the square of the armature current
(A) DC shunt motor
(B) stepper motor
(C) 2-phase servomotor
(D) DC series motor
Ans: D
Ta .Ia and Ia ; therefore Ta Ia2
Q.61 The synchronous speed for a 3 phase 6-pole induction motor is 1200 rpm. If the
number of poles is now reduced to 4 with the frequency remaining constant, the rotor
speed with a slip of 5% will be _________.
(A) 1690 rpm
(B) 1750 rpm
(C) 1500 rpm
(D) 1710 rpm
Ans: D
Given : Ns1 =1200 , P1= 6,
P2 = 4, s = 0.05,
Frequency f = NsP/120
= 1206/120 = 60 Hz
rotor frequency f/ = s.f = 0.05 60 = 3.0 Hz
Now, Ns2 = 120 60 /4 = 1800 and Ns – N = 120 f / P2
Therefore, N=Ns- 120 f / P2 = 1800-1200.0560/4 = 1800-90 = 1710
Q.62 The eddy current loss in an a-c electric motor is 100 watts at 50 Hz. Its loss at 100
Hz will be
(A) 25 watts
(B) 59 watts
(C) 100 watts
(D) 400 watts
Ans: D
Eddy current losses f2
New loss (2f)2
New loss 4f2
\ 4 times
Q.63 The maximum power for a given excitation in a synchronous motor is developed
when the power angle is equal to
(A) 0o
(B) 45o
(C) 60o
(D) 90o
Ans: A
P = VI cosF
Pmax = VI
\F = 00
Q. 64 A commutator in a d.c. machine
(A) Reduces power loss in armature.
(B) Reduces power loss in field circuit.
(C) Converts the induced a.c armature voltage into direct voltage.
(D) Is not necessary.
Ans: C
As name suggests, it commutes ac into dc.
Q.65 The speed of a d.c. shunt motor at no-load is
(A) 5 to 10%
(B) 15 to 20%
(C) 25 to 30% (
D) 35 to 40%
higher than its speed at rated load.
Ans: A
Ta F Ia ,, F = constant,
\T Ia
N Eb / F or N Eb initially Eb less , so speed is less.
Q.66 The efficiency of a transformer is mainly dependent on
(A) core losses.
(B) copper losses.
(C) stray losses.
(D) dielectric losses.
Ans: A
Core loss has prominent value over other losses
Q.67 When two transformers are operating in parallel, they will share the load as under:
(A) proportional to their impedances.
(B) inversely proportional to their impedances.
(C) 50% – 50%
(D) 25%-75%
Ans: A
High rating transformer has higher impedance.
kVA rating Impedance of transformer
Q.68 If the voltage is reduced to half, the torque developed by an induction motor will be
reduced to
(A)41of original torque.
(B)21of original torque.
(C)81of original torque.
(D)161of original torque.
Ans: B
Tg V or Tg Pm (rotor gross output)
Q.69 A 3-phase, 400 votts, 50 Hz, 100 KW, 4 pole squirrel cage induction motor with a
rated slip of 2% will have a rotor speed of
(A) 1500 rpm
(B) 1470 rpm
(C) 1530 rpm
(D) 1570 rpm
Ans: B
N = NS (1-S) and NS =120 f / p
=120 x 50 /4 = 1500 rpm
\N= 1500 (1-0.02) =1470 rpm
Q.70 If the phase angle of the voltage coil of a directional relay is o
50 , the maximumtorque angle of the relay is
Ans: C
Torque Power
Power Voltage
Therefore, It has same angle as ‘V’ has
Q.71 The voltage at the two ends of a transmission line are 132 KV and its reactance is
40 ohm. The Capacity of the line is
(A) 435.6 MW
(B) 217.8 MW
(C) 251.5 MW
(D) 500 MW
Ans: A
Line capacity is determined by power of line
P = (V2/R) or (V2/Z) when cos F =1
Q.72 A 220/440 V, 50 Hz, 5 KVA, single phase transformer operates on 220V, 40Hz
supply with secondary winding open circuited. Then
(A) Both eddy current and hysteresis losses decreases.
(B) Both eddy current and hysteresis losses increases.
(C) Eddy current loss remains the same but hysteresis loss increases.
(D) Eddy current loss increases but hysteresis loss remains the same.
Ans: A
Wh = khfBm
1.6 and We = kef2Bm
2.k
Therefore, hysteresis and eddy current losses will be decreased when frequency
decreases.
Q.73 A synchronous motor is operating on no-load at unity power factor. If the field
current is increased, power factor will become
(A) Leading & current will decrease
(B) Lagging & current will increase.
(C) Lagging & current will decrease.
(D) Leading & current will increase.
Ans: A
Initially synchronous motor is operating at no load and unity power factor. When
field current increases, the excitation will increase. Therefore, p.f will be leading and
current will be I CosF < I
Q.74 A d.c. shunt motor runs at no load speed of 1140 r.p.m. At full load, armature reaction weakens the main flux by 5% whereas the armature circuit voltage drops by 10%. The
motor full load speed in r.p.m. is
(A) 1080
(B) 1203
(C) 1000
(D) 1200
Ans: A
N2 / N1 =Eb2 /Eb1 x F1 / F2 ; F2 = 0.95F1 ; Eb2 = 0.9Eb1
\ N2 /1140 = 0.9 x 1/0.95
N2 = 1080
Q.75 The introduction of interpoles in between the main pole improves the performance ofd.c. machines, because
(A) The interpole produces additional flux to augment the developed torque.
(B) The flux waveform is improved with reduction in harmonics.
(C) The inequality of air flux on the top and bottom halves of armature isremoved.
(D) A counter e.m.f. is induced in the coil undergoing commutation.
Ans: D
Counter e.m.f is produced, it neutralizes the reactive emf.
Q.76 The rotor power output of a 3-phase induction motor is 15 KW and corresponding slipis 4%. The rotor copper loss will be
(A) 600 W.
(B) 625 W
(C) 650 W
(D) 700 W
Ans: B
Rotor copper losses = rotor input- rotor output
and output = (1-s) input
\ Input = output/(1-s) = 15000 /1-0.04 = 15625
\ loss = 15625 -1500 = 625 watt
Q.77 The direction of rotation of hysteresis motor is reversed by
(A) Shift shaded pole with respect to main pole
(B) Reversing supply lead
(C) Either A or B
(D) Neither A nor B
Ans: A
This motor used single phase, 50Hz supply and stator has two windings. These areconnected continuously from starting to running.
Q.78 A 1.8°step, 4-phase stepper motor has a total of 40 teeth on 8 pole of stator. Thenumber of rotor teeth for their rotor will be
(A) 40
(B) 50
(C) 100
(D) 80
Ans: B
Step angle ‘’ = NS – Nr / NS Nr x 3600
\ 1-8 = -40 + Nr/40 Nr x 3600
Nr = 50
Q.79 Low head plants generally use
(A) Pelton Turbines
(B) Francis Turbine
(C) Pelton or Francis Turbine
(D) Kaplan Turbines
Ans: A
In the hysterisis motor, the direction of rotation can be reversed by shifting theshaded pole region with respect to main pole. But not by changing supply lead
because it has ac supply.
Q.80 The charging reactance of 50 Km length of line is 1500. The charging reactance for100Km length of line will be
(A) 1500
(B) 3000
(C) 750
(D) 600
Ans: B
Characteristic reactance per km = 1500/50 = 30 ohms
\ Characteristic reactance per 100km = 30 x 100 = 3000 ohms
Q.81 Electric ovens using heating elements of _______________ can produce temperatureupto 3000°C.
(A) Nickel
(B) Graphite
(C) Chromium
(D) Iron
Ans: C
Chromium has high melting point.
Q.82 In DC generators, armature reaction is produced actually by
(A) Its field current.
(B) Armature conductors.
(C) Field pole winding.
(D) Load current in armature.
Ans: D
Because load current in armature gives rise to armature mmf which react with
main field mmf.
Q.83 Two transformers operating in parallel will share the load depending upon their
(A) Rating.
(B) Leakage reactance.
(C) Efficiency.
(D) Per-unit impedance.
Ans: A
Transformers having higher kVA rating will share more load.
Q.84 As compared to shunt and compound DC motors, the series DC motor will have thehighest torque because of its comparatively ____________ at the start.
(A) Lower armature resistance.
(B) Stronger series field.
(C) Fewer series turns.
(D) Larger armature current.
Ans: D
T F Ia
(before saturation)
F Ia
T Ia
2
Q.85 A 400kW, 3-phase, 440V, 50Hz induction motor has a speed of 950 r.p.m. on fullload.The machine has 6 poles. The slip of the machine will be _______________.
(A) 0.06
(B) 0.10
(C) 0.04
(D) 0.05
Ans: D
N = Ns (1-S)
950 = 120 x 50 (1-S)/6
S = 0.05
Q.86 Reduction in the capacitance of a capacitor-start motor, results in reduced
(A) Noise.
(B) Speed.
(C) Starting torque.
(D) Armature reaction.
Ans: C
Reduction in the capacitance reduces starting voltage, which results in reducedstarting torque.
Q.87 Regenerative braking
(A) Can be used for stopping a motor.
(B) Cannot be easily applied to DC series motors.
(C) Can be easily applied to DC shunt motors
(D) Cannot be used when motor load has overhauling characteristics.
Ans: B
Because reversal of Ia would also mean reversal of field and hence of Eb
Q.88 At present level of technology, which of the following method of generating electric power from sea is most advantageous?
(A) Tidal power.
(B) Ocean thermal energy conversion
(C) Ocean currents.
(D) Wave power.
Ans: A
At present level of technology, tidal power for generating electric power from seais most advantageous because of constant availability of tidal power.
Q.89 If the field circuits of an unloaded salient pole synchronous motor gets suddenly opencircuited, then
(A) The motor stops.
(B) It continues to run at the same speed.
(C) Its runs at the slower speed.
(D) It runs at a very high speed.
Ans: B
The motor continues to run at the same speed because synchronous motor speeddoes not depend upon load, Na f.
Q.90 Electric resistance seam welding uses __________ electrodes.
(A) Pointed
(B) Disc.
(C) Flat
(D) Domed
Ans: B
Disc type electrodes are used for electric resistance seam welding.
Q.91 For LV applications (below 1 kV), ______________ cables are used.
(A) Paper insulated.
(B) Plastic.
(C) Single core cables.
(D) Oil filled.
Ans: C
For low voltage applications single core cables are suitable.
Q.92 No load current in a transformer:
(A) lags the applied voltage by 90°
(B) lags the applied voltage by somewhat less than 90°
(C) leads the applied voltage by 90°
(D) leads the applied voltage by somewhat less than 90°
Ans: B
The primary input current under no load conditions has to supply (i) iron losses inthe core i.e hysteresis loss and eddy current loss (ii) a very small amount of Cu loss
in the primary (there being no Cu loss in secondary as it is open)
Q.93 A transformer operates most efficiently at 3/4th full load. Its iron (PI) and copperloss (PCu) are related as:
(A) =16 9 I Cu P P
(B) = 4 3 I Cu P P
(C) = 3 4 I Cu P P
(D) = 9 16 I Cu P P
Ans: D
If PCu is the Cu loss at full load, its value at 75% of full load isPCu x(0.75)2 = 9/16 PCu
At maximum efficiency, it equals the iron loss PI which remains constant through
out. Hence max. efficiency at
PI = 9/16 PCu
Or PI / PCu = 9/16
Q.94 In a salient pole synchronous machine (usual symbols are used):
(A) xq > xd
(B) xq = xd
(C) xq < xd
(D) xq = 0
Ans: C
Since reluctance on the q axis is higher, owing to the larger air gap,
hence xq < xd
Q.95 The armature of a dc machine is laminated to reduce:
(A) Eddy current loss
(B) Hysteresis loss
(C) copper losses
(D) friction and windage losses
Ans: A
Thinner the laminations, greater is the resistance offered to the induced e.m.f.smaller the current and hence lesser the I2R loss in the core.
Q.96 The resistance representing mechanical output in the equivalent circuit of aninduction motor as seen from the stator is:Mechanical Power developed by the rotor (Pm) or gross power developed by rotor
(Pg)
= rotor input –rotor Cu losses
= (3I/2 R2
/ / S) -(3I/2 R2
/ )
= 3I/2 R2
/ (1/ S -1)
Q.97 A single phase Hysteresis motor
(A) can run at synchronous speed only
(B) can run at sub synchronous speed only
(C) can run at synchronous and super synchronous speed
(D) can run at synchronous and sub synchronous speed
Ans: A
The rotor revolves synchronously because the rotor poles magnetically lock up with the revolving stator poles of opposite polarity
Q. 98 The temperature of resistance furnaces can be controlled by changing the:
(A) applied voltage
(B) number of heating elements
(C) circuit configuration
(D) All of the above
Ans: D
Temperature of resistance furnaces can be controlled by changing either appliedvoltage or by number of heating elements or by circuit configuration.
Q.99 The line trap unit employed in carrier current relaying:
(A) offers high impedance to 50 Hz power frequency signal
(B) offers high impedance to carrier frequency signal
(C) offers low impedance to carrier frequency signal
(D) Both (A) & (C)
Ans: B
The line trap unit employed in carrier current relaying offers high impedance tocarrier frequency signal.
Because carrier frequency range is 35 km – 500 kHz
XL = 2 f l
Where f increases XL will also increases
Q.100 For a line voltage V and regulation of a transmission line R
(A) R µ V
(B)VR µ 1
(C) 2 R µ V
(D) 2 VR µ 1
Ans: B
R 1/V
Regulation = (V0 – VL ) / V0 , if VL is high the (V0 – VL ) will be low.
Therefore R 1/
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ONGC previous years ComputerEngineering questions with answers
1. What is the name of the software that allows us to browse through web pages?
(a) Browser
(b) Mail Client
(c) FTP Client
(d) Messenger
2. What is the address given to a network called?
(a) System Address
(b) SYSID
(c) Process ID
(d) IP Address
3. Which one of the following is a valid DOS command?
(a) LIST *.*
(b) LIST???.???
(c) RECOVER A:
(d) RENAME A:SAMPLE.TXT C:TEST.DOC
4. All system settings in WINDOWS are stored in:
(a) CONTROL.INI
(b) MAIN.INI
(c) SYSTEM.INI
(d) SETTING.INI
5. Which number system is usually followed in a typical 32-bit computer?
(a) 2
(b) 10
(c) 16
(d) 32
6. Which of the following is not an output device:
(a) Printer
(b) Scanner
(c) Flat Screen
(d) Touch Screen
7. A microprocessor is a processor with reduced
(a) instruction set
(b) power requirement
(c) MIPS performance
(d) none of the above
8. Which of the following is not an output of an assembler?
(a) executable program
(b) source listing with line numbers and errors
(c) a symbol table
(d) object program
9. Which layer of OSI model is responsible for routing and flow control:
(a) Presentation
(b) Transport
(c) Network
(d) Data Link
10. Arrays are passed as arguments to a function by
(a) value
(b) reference
(c) both a and b
(d) none of the above
11. Array is:
(a) linear data structure
(b) non-linear structure
(c) none of the above
12. A data structure in which elements are added and removed from only one end, is known as:
(a) Array
(b) Stack
(c) Queue
(d) None of the above
13. A diamond-shaped box in an Entity-Relationship diagram refers to:
(a) Entity
(b) Relationship
(c) Attribute
14. The principle means of identifying entities within an entity set is:
(a) Primary Key
(b) Record
(c) Attribute
(d) Tuple
15. Modem refers to:
(a) Modulator
(b) Modulation
(c) Demodulator
(d) Modulator and Demodulator
16. C language is available for which of the following Operating Systems?
(a) DOS
(b) Windows
(c) Unix
(d) All of the above
17. Which of the following have the fastest access time?
(a) Magnetic Tapes
(b) Magnetic Disks
(c) Semiconductor Memories
(d) Compact Disks
18. DMA stands for:
(a) Direct Memory Allocation
(b) Distinct Memory Allocation
(c) Direct Memory Access
(d) Distinct Memory Access
19. Array subscripts in C always start at:
(a):1
(b) 0
(c) 1
(d) Value provided by user
20. Which type of commands in DOS needs additional files for their execution?
(a) Batch Commands
(b) Internal Commands
(c) External Commands
21. Which of the following statements in regard to Directories is false?
(a) Directories can exist inside directories
(b) The root directory is always at the highest level
(c) Directories with files can be deleted
(d) Directories cannot be renamed
22. It is better to buffer a table when
(a) When a table is read infrequently
(b) When a table is linked to check tables
(c) When a table is read frequently and the data seldom changes
(d) When a single record is to be picked up
23. The Operating System is responsible for:
(a) Controlling peripheral devices such as monitor, printers, disk drives
(b) Provide an interface that allows users to choose programs to run and to manipulate files
(c) Manage users’ files on disk
(d) All of the above
24. A company whishes to connect two sites in different parts of the country together. It is decided to use the telephone system. What device should be connected to the fileservers on each site?
(a) Router
(b) Modem
(c) Switch
(d) Hub
25. What is a file server?
(a) A computer that performs a service for other computers
(b) A computer that controls the printers on the network
(c) A computer that stores files that are created by network users
26. What is the Protocol used for the Internet?
(a) IPX/SPX
(b) NetBIOS/NetBEUI
(c) CDMA/CA
(d) TCP/IP
27. Which one of the following is not a Normal Forms (Normalization) rule with regards to the Relational Model?
(a) All fields within a table must relate to or directly describe the Primary Key.
(b) Repeating Groups must be eliminated from tables.
(c) Fields that can contain non-numeric data are to be removed and placed within their own tables with an associated Primary Key.
(d) Redundant data is to be eliminated by placing the offending fields in another table.
28. Choose the answer which best describes the term Primary Key:
(a) The Primary Key is a field that contains data that can be duplicated.
(b) The Primary Key is a field that contains data that is unique.
(c) The Primary Key is a field that is never associated with any field in other tables.
(d) The Primary Key field is a concept used only in Microsoft Access.
29. Which technique is used to reduce the size of a file:
(a) Compression
(b) Decompression
(c) Encryption
(d) Decryption
30. BIOS stands for
(a) Binary Input Output Set
(b) Binary Input Output System
(c) Basic Input Output Set
(d) Basic Input Output System
31. A floppy disk is consisting of 40 tracks, each track contains 100 sectors, and the capacity of a sector is 512 bytes, what is the approx. size of that disk?
(a) 1 MB
(b) 2 MB
(c) 4 MB
(d) 8 MB
32. What is the binary equivalent of a decimal number 68:
(a) 1000100
(b) 1100100
(c) 1000010
(d) 1000001
33. Assembly language to machine language translation is:
(a) One-to-One
(b) One-to-Many
(c) Many-to-One
(d) Many-to-Many
34. Maximum size of IP address is:
(a) 12 bits
(b) 24 bits
(c) 32 bits
(d) 48 bits
35. RAM stands for
(a) Read Access Memory
(b) Read After Memory
(c) Random Access Memory
(d) Random After Memory
36. What is the final value of sum?
main ()
{
int sum=1;
for(;sum<=9;)
printf(%d\n, ++sum);
}
(a) 9
(b) 10
(c) 11
(d) none of the above
37. If c is a variable initialized to 1, how many times the following loop be executed:
while(c>0 && c<60)
{
c++;
}
(a) 59
(b) 60
(c) 61
(d) none of the above
38. The declaration void fun(int) indicates the fun is a function which:
(a) has no arguments
(b) returns nothing
(c) both a and b
(d) none of the above
39. Out of the following which is not valid network topology:
(a) Bus
(b) Star
(c) Circle
(d) Tree
40. The overall logical structure of a database can be expressed graphically by:
(a) Data Flow Diagram
(b) Flow Chart
(c) Directed Graph
(d) Entity-Relationship Diagram
41. CARRY, in a half-adder, can be obtained using:
(a) OR gate
(b) AND gate
(c) EX-OR gate
(d) EX-AND gate
42. The memory that requires refreshing of data is:
(a) SROM
(b) DROM
(c) SRAM
(d) DRAM
43. The minimum number of bits required to represent numbers in the range:28 to +31 is-
(a) 5
(b) 6
(c) 7
(d) 8
44. Which bus carries information between processors and peripherals?
(a) Data bus
(b) Control bus
(c) Address bus
(d) Information bus
45. Which part of the computer perform arithmetic calculations?
(a) Control unit
(b) Registers
(c) ALU
(d) CPU
46. A gigabyte represents:
(a) 1 billion bytes
(b) 1000 kilobytes
(c) 230 bytes
(d) 10 megabytes
47. The minimum number of bits required to store the hexadecimal number FF is:
(a) 2
(b) 4
(c) 8
(d) 16
48. Cache memory enhances:
(a) memory capacity
(b) memory access time
(c) secondary storage capacity
(d) secondary storage access time
49. A UPS:
(a) increases the storage capacity of a computer system
(b) increases the processor speed
(c) provides backup power in the event of a power cut\
(d) none of the above
50. An RDBMS is a:
(a) Remote DBMS
(b) Relative DBMS
(c) Reliable DBMS
(d) Relational DBMS
ONGC previous years electrical Engineering questions with answers ,ONGC-Oil and Natural Gas Corporation Limited (ONGC) exam 2012,2011,2010,2009 Free Question Papers Answers Previous Year Old Placement Paper ONGC upcoming graduate trainee 2012 notification, selection procedure and test pattern, ONGC graduate trainees for ECE,EEE,Mechnical…..ONGC 2011 Written test questionsThe total questions were 124 out of which 40 questions from G.K. and 80 questions from technical and 4 questions were descriptive. written test examination dates and previous years solved question papers with answers,ONGC free solved sample placement papers and technical interview questions with answers,ONGC Interview procedure, ONGC Aptitude, reasoning test papers,ONGC complete prepratory tool and tips to crack all IT NON-IT and IBPS,Bank written test examination questions papers with detailed solutions
1 A single phase transformer is connected to a supply of voltage V and frequency f and is supplying a load, connected across its secondary winding.
If the supply voltage is reduced from V to V/2, the flux established in the core will
decrease by nearly 50%
increase by nearly 50%
remain unchanged
be affected by amount of load and not by the applied voltage
2 Under magnetic saturation of the core of a transformer, the reactance parameters of its equivalent circuit are affected such that
X1 and X2 increase while Xm does not change
X1 and X2 do not change while Xm decreases
X1 and X2 do not change while Xm increases
X1 and X2 decreases while Xm does not change
3 A single phase 2000/200 V, 10 kVA, two winding transformer is reconnected as a step-up autotransformer with 2000 V winding as primary. The kVA rating of the autotransformer shall be
10 kVA
11 kVA
110 kVA
220 kVA
4 The power factor at which power is drawn by a transformer is
very low under O.C. test but high under S.C. test
high under O.C. test but low under S.C. test
low both under O.C. and S.C. tests
high both under O.C. and S.C. tests
5 The O.C.C. of a shunt d.c. generator is represented by E = 12+66I. If the field resistance is 70 ohms, the no-load voltage of the generator will be
144 V
210 V
220 V
288 V
6 In d.c. shunt motors, the developed torque is proportional to
induced e.m.f.
armature current
output power
line current
7 The speed of a separately excited d.c. motor can be controlled below base speed by (a) armature resistance control and (b) supply voltage control. What happens to the slope of modified speed-torque characteristics under the two methods?
It changes in both types of control
It remains unchanged in both types of control
It remains unchanged in armature resistance control while changes in supply voltage control
It remains unchanged in supply voltage control while changes in armature resistance control
8 The polarity of interpoles used in d.c. machines is
same as the main pole ahead in generators while opposite of the main pole ahead in motors
same as the main pole ahead ion motors while opposite of the main pole ahead in generators
same as the main pole ahead in both motors and generators
opposite of the main pole ahead in both motors and generators
10 In synchronous generators, examine the following statements about voltage regulation:
Synchronous impedance method gives pessimistic results
MMF method gives optimistic results
In unsaturated machine both methods (synchronous impedance and MMF) give same result
11 Which of the statements are correct?
1, 2 and 3
Only 1 and 2
Only 3
Only 2 and 3
12 Under symmetrical short circuit of a synchronous generator, the armature reaction is
magnetizing
demagnetizing
cross-magnetising
mainly magnetising
13 In synchronous generators, the fifth harmonic in induced emf can be eliminated by using coils show chorded by an angle
9o
18o
27 o
36o
14 In induction motor operation, a slip greater than 1 refers to
regenerative braking
motoring in reverse direction
plugging
dynamic braking
15 As the applied voltage to an induction motor, operating under no-load, is reduced to half
its speed reduced and stator current increases
its speed reduced and stator current also reduces
its speed reduces but there is not change in stator current
there is no change in speed but stator current reduces
16 A 3-phase induction motor is delivering a load of 10 kW at a lagging p.f. of 0.5. If a 3-phase capacitor bank of 7.3 kVAR is connected at its input, the resulting kVA drawn from supply shall be (approximately)
26.5
24.5
20.0
14.0
17 An electric motor developing a starting torque of 10 Nm starts with a load of 6 Nm at its shaft. If the acceleration at start is 2 rad/sec2 , the moment of inertia of the system must be
2 kg-m2
2 N-m2
0.5 kg-m2
0.5 N-m2
18 A synchronous motor works as a synchronous condenser if
underexcited
overexcited
excited with 100% excitation
unexcited
19 In relation to damper bar winding in a synchronous motor, examine the following statements:
Damper bars are provided in slots on poles
Damper bars improve excitation
Damper bars help the motor self start
Damper bars minimize hunting.
20 Which of the statements are correct?
1, 2, 3
2, 3
1, 4
1, 3, 4
21 In large power ratings, synchronous motor is considered superior to induction motor, since
it is less expensive
its efficiency is better
it can be operated at better power factor
its speed regulation is superior.
22 An induction motor drive is designed for two speed operation. For this purpose, the motor is provided with two windings on its stator corresponding to 4 poles and 8 poles. While the motor was running on 4 pole winding, a changeover to 8 pole winding is made. The motor will
experience dynamic braking
experience regenerative braking
experience no braking but will slow down due to its inertia
draw dangerously high current
23 A thyristor which is in ON state is to be switched OFF. For this purpose a reverse bias is applied across it. Examine the following statements regarding flow of current from anode to cathode (forward current):
Forward current can continue to flow if the circuit is purely resistive
Forward current can continue to flow if the circuit is dominantly inductive
Forward current can continue to flow if the circuit is dominantly capacitive
Forward current will immediately stop flowing.
Which of the above statements are correct?
Only 4
Only 1
Only 2 and 3
Only 2
24 In a 3-phase full controlled thyristor bridge rectifier operating under continuous conduction mode, each thyristor conducts for
180o and two thyristors conduct at a time
120o and three thyristors conduct at a time
180o and three thyristors conduct at a time
120o and two thyristors conduct at a time
25 A single phase full controlled rectifier can work as inverter, if the firing angle is between
0o and 90o
60o and 90o
90o and 180o
0o and 60o
26 The grading capacitors are provided across the series connected interrupters in EHV circuit breakers for
reducing short circuit current
improving power factor
equalizing distribution of recovery voltage across the interrupters
preventing inductive current chopping.
27 The minimum cost operating condition for a thermal plant is that
the larger units should generate more power as compared to smaller units
the smaller units should generate more power as compared to larger units
the incremental cost rate of the units be proportional to their rating
the incremental cost rate of all the units be equal
23 A d.c. shunt motor drive of 100 h.p. is run (a) at half the rated speed by armature voltage control and (b) at 1.5 times the rated speed by field control. Its power rating in the two cases shall be modified as
100 h.p. in both cases
50 h.p. in case (a) and 150 h.p. in case (b)
50 h.p. in case (a) and 100 h.p. in case (b)
100 h.p. in case (a) and 150 h.p. in case (b)
24 A single phase full controlled rectifier can work as inverter, if the firing angle is between
0o and 90o
60o and 90o
90o and 180o
0o and 60o
25 When d.c. voltage is converted to a.c. by an inverter, PWM technique is used to
control only the output voltage from within the inverter
control both the output voltage and frequency from within the inverter
control the output current
reduce losses in the inverter
28 The effect of earth on a three-phase transmission line is to
increase its capacitance and decrease inductance
decrease its capacitance and increase inductance
increase its capacitance without affecting inductance
increase its inductance without affecting capacitance.
29 In case of a transmission line if the voltage regulation is negative, then the load power factor is
zero
lagging
unity
leading
30The voltage gradient at the surface of a cable, having a conductor of radius r and a sheath of radius R, is minimum when
R = r/e
R = r
R =er
R = er
31 In an N-bus power system with M-PV buses, the size of the Jacobian matrix for load flow calculation is
N×N
(N-M) ×(N-M)
(N-1) × (N-1)
(N-M-1) × (N-M-1)
32The zero-sequence equivalent circuit of a delta-star transformer, with solidly grounded neutral, is
33 The plug setting multiplier of a 5 Amp. IDMT relay for a fault current of 4000 Amp. and a relay setting of 125%, with a C.T. ratio of 80 will be
34 If the cost of electricity generation is to be reduced then
the diversity factor and load factor both should be low
the diversity factor and load factor both should be high
the diversity factor should be high while the load factor should be low
the diversity factor should be low and the load factor should be high
35 The coefficients of reflection for voltage and current for an open ended line are respectively
1.0 and -1.0
-1.0 and 1.0
1.0 and -1.0
36 If G is the MVA rating of a synchronous machine with inertia constant H sec. and operating frequency f, then the angular momentum M of the machine, in MJ-sec/electrical degree, is
37 Circular grooves are provided underneath the insulator disc for
reducing the weight of the disc
improving disc strength
38The arc formation in vacuum circuit breaker is initiated by
field emission
thermal emission
photo emission
secondary emission
39The series reactors are used to
limit over voltages
control Ferranti effect
limit fault current
improve stability
40If the spacings Dab, Dbc and Dca between the phases a, b, and c of a three phase transmission line are not equal, then the equivalent spacing Deq can be calculated as
(Dab + Dbc + Dca)/3
(Dab * Dbc * Dca)/3
(Dab + Dbc + Dca)1/3
Dab * Dbc * Dca)1/3
41For calculating fault current for a double line to ground fault in an ungrounded system
positive, negative and zero sequence networks are connected in series
positive, negative and zero sequence networks are connected in parallel
positive and negative sequence networks are connected in parallel
positive and negative sequence networks are connected in series
42The unit of R, the regulation constant of turbine speed governor, is
Hz/MW
MW/sec
MW/Hz
MW-Hz
43 If in a power system the line to line base voltage is VB kV and the 3-phase base MVA is SB, then the base impedance of the system is
44The pumped storage hydro plants are used as
Base load plants
Peak load plants
Mid-range plants
both (A) and (B)
45The specified operating criteria for the proper operation of interconnected power system is , that Area Control Error (ACE) must be zero at least once in a
1 sec period
1 min period
10 min period
1 hr period
46If a network has b branches and n nodes, then the number of independent KVL equations for the network are
b-n
n-b+1
b-n-1
b-n+1
47What will be the value of ZL for maximum power transfer condition in the circuit shown in Fig. Q.47?
48 Which of the following statements does not apply to series RLC circuit?
The current and the admittance are maximum at resonance
The phase angle of the impedance changes from +90o to –90o as the frequency is varied from 0 to ¥
The total stored energy in the circuit is constant at resonance
The power factor is unity at resonance
49 The average value of a sine wave over a full cycle is
50A two port network is reciprocal and symmetrical, if ABCD parameters satisfy the conditions:
AB-CD = 1 and A = D
AD-BC = 1 and A = D
AC-BD = 1 and A = D
AD-BC = 1 and B = C
Oil and Natural Gas Corporation is the government undertaking that works under the Ministry of Petroleum and Gas.We have given the ONGC Graduate Trainee previous papers of civil below.Read the ONGC graduate trainee previous year question papers to analyze the exam pattern and important topics in the subject for the better preparation to get good score in the examination.
ONGC Model Question Paper
Civil Engineering
1. Which one of the following tests is performed in the laboratory to determine the extent of weathering of aggregates for road works?
(a) Soundness test
(b) Crushing test
(c) Impact test
(d) Abrasion test
Ans. (a)
2. Which one of the following geometric features requires the magnitudes of weaving angle and weaving distance for its design?
(a) Rotary design
(b) Right-angle intersection
(c) Roundabout
(d) Grade-separated junction
Ans. (a)
3. Which one of the following methods is used in the design of rigid pavements?
(a) CBR method
(b) Group index method
(c) Westergaard?s method
(d) McLeod?s method
Ans. (c)
4. In which one of the following yards, are reception, sorting and dispatch of railway wagons done?
(a) Loco yard
(b) Marashalling yard
(c) Goods yard
(d) Passenger yard
Ans. (b)
5. Which one of the following is not a desirable property of the subgrade soil as a highway meterial?
(a) Stability
(b) Ease of compaction
(c) Good drainage
(d) Bitumen adhesion
Ans. (d)
6. Consider the following statements:
In surverying operations, the word ?reciprocal? can be associated with
1. ranging
2. levelling
3. contouring
Which of the above statements is/are correct?
(a) 1 only
(b) 1 and 2 only
(c) 2 and 3 only
(d) 1, 2 and 3
Ans. (b)
7. How many- sidereal days are there in a solar year?
(a) 365.2840
(b) 366.2422
(c) 360.2500
(d) 365.0000
Ans. (b)
8. Consider the following statements
A sidereal year can be defined as the time interval:
1. between two successive transits .of the sun through the meridian of any of the fixed stars
2. between two successive passages of the sun through perigee
Which of the above statements is/are correct?
(a) 3 only
(b) 1and 2
(c) 2 and 3
(d) 1 only
Ans. (b)
9. Which one of the following methods of computing area assumes that the short, lengths of the boundary between the ordinatesm are parabolic ares?
(a) Average ordinate rule
(b) Middle ordinate rule
(c) Simpson?s rule
(d) Trapezoidal rule
Ans. (c)
10. Which one the following errors is more severe in plane-table surveying?
(a) Defective sighting
(b) Defective orientation
(c) Movement of board between sights
(d) Non-horizontality of board when points sighted are at large differences of their elevation .
Ans. (b)
11. Which one of the following sets of factors is related to design of thickness rigid pavement by Westergaard method?
(a) CBR value and stiffness index of soil
(b) Deflection factor and traffic index
(c) Swelling index and bulk modulus
(d) Radius of relative stiffness and modulus of subgrade reaction
Ans. (d)
12. Consider the following in relation to group index of soil:
1. Liquid limit
2. Sandy loam
3. Plasticity index
4. Per cent passing 75 microns sieve
Which of the above is/are used for estimating the group index?
(a) 1 only
(b) 1and 2
(c) 2 and 3
(d) 1, 3 and 4
Ans. (d)
13. Which set of traffic functional design as well as for ?highway capacity? design?
(a) Origin and destination studies
(b) Parking and accident studies
(c) Speed and volume studies
(d) Axle load studies
Ans. (a)
14. Which one of the following traffic survey schemes is most relevant when deciding on locating major ?routes? in a city?
(a) Traffic volume survey
(b) Origin and destination survey
(c) Speed survey
(d) Traffic capacity survey
Ans. (b)
15. Which one of the following equipments is useful in determining spot speed in traffic engineering?
(a) Endoscope
(b) Periscope
(c) Radar
(d) Tachometer
Ans. (c)
16. Hot bitumen is sprayed over freshly constructed bituminous surface followed by spreading of 6.3 mm coarse aggregates and rolled. Which one of the following is indicated by this type of construction?
(a) Surface dressing
(b) Gravel-bitumen mix
(c) Liquid seal coat
(d) Seal coat
Ans. (a)
17. Radius of relative stiffness of cement concrete pavement does not depend upon which one of the following?
(a) Modulus of subgrade reaction
(b) Wheel load
(c) Modulus of elasticity of cement concrete
(d) Poisson?s ratio of concrete
Ans. (b)
18. For conditions obtaining in India, at which location in a cement concrete payement will the combined stresses due to traffic wheel studies is needed for well as for ?highway load and temperature have to be critically checked during design?
(a) Corner
(b) Corner and interior
(c) Corner and edge
(d) Corner, edge and interior
Ans. (d)
19. Consider the following factors:
1. The change in the shape and size of the channel cross-section
2. The change in the slope of the channel
3. The presence of obstruction
4. The change in the frictional forces at the boundaries
Which of the above factors would cause a gradually varied flow?
(a) 1, 2, 3 and 4
(b) 1, 2 and 3 only
(c) 2 and 4 only
(d) 3 and 4 only
Ans. (a)
20. Under which one of the following categories is the river Ganga classified in the reach through UP and Bihar?
(a) Straight river
(b) Meandering river
(c) Braided river
(d) Deltaic river
Ans. (b)
21. Which of the following categories best describes the Hirakud reservoir?
(a) Reservoir for irrigation and power
(b) Reservoir for flood control, power and irrigation
(c) Reservoir for irrigation and water supply
(d) Reservoir for recreation and fishery
Ans. (b)
22.. During a particular stage of the growth of a crop, consumptive use of water is 2.8 mm/day. If the amount of water available in the soil is 25% of 80 mm depth of water what is the frequency of irrigation?
(a) 9 days
(b) 13 days
(c) 21 days
(d) 25 days
Ans. (c)
23.. Consider the following statements:
Irrigation water has to be supplied to the crops when the moisture level falls
1. below field capacity
2. to wilting point
3. below wilting point
Which of the above statement is/are correct?
(a) 1 only
(b) 2 only
(c) 3 only
(d) 2 and 3
Ans. (a)
24.. A groundwater basin consists of 10 km2 area of plains. The maximum groundwater table fluctuation has been observed to be 1.5 m. Consider specific yield of the basin as 10%. What is the available groundwater storage in million cubic metres?
(a) 1.0
(b) 1.5
(c) 2.5
(d) 2.0
Ans. (b)
25. Consider the following chemical emulsions:
1. Methyl alcohol
2. Cetyl alcohol
3. Stearyl alcohol
4. Kerosene
Which of the above chemical emulsions is/are used to minimize the loss of water through the process of evaporation?
(a) 1 only
(b) 1 and 4
(c) 2 and 4
(d) 2 and 3
Ans. (d)
26. A catchment area of 60 ha has a runoff coefficient of 0.40. If a storm of intensity 3cm h and duration longer than the time of concentration occurs in the catchment, then what is the peak discharge?
(a) 2.0 m3/s
(b) 3.5 m3/s
(c) 4.5 m3/s
(d) 2.5 m3/s
Ans. (a)
27. Which combination of surface water quality parameters will indicate sweep coagulation as the preferred mechanism of coagulation?.
(a) High turbidity ? low alkalinity
(b) High turbidity ? high alkalinity
(c) Low turbidity ? high alkalinity
(d) Low turbidity ? low alkalinity
Ans. (b)
28. In a canal irrigation project, 76% of the culturable command area (CCA) remained without water during Kharif season; and 58% of CCA remained without water during Rabi season in a particular year. Rest of the areas got irrigated in each crop respectively. What is the intensity of irrigation for the project in that year?
(a) 134%
(b) 76%
(c) 66%
(d) 58%
Ans. (b)
29. What is the critical combination of vertical and horizontal earthquake accelerations to be considered for checking the stability of a gravity dam in reservoir full condition?
(a) Vertically upward and horizontally downstream
(b) Vertically upward and horizontally upstream
(c) Vertically downward and horizontally upstream
(d) Vertically downward and horizontally downstream
Ans. (d)
30. What is the height of wave which is likely to be generated by a wind of 80 km/hr in a reservoir having a fetch of 50 km:
(a) 0.5m
(b) 1.0 m
(c) 2.0 m
(d) 3.0 m
Ans. (c)
31. Consider the following statements:
1. Giving equal weightings to horizontal and vertical creeps for design of weir foundations is one of the drawbacks of Kennedy?s theory.
2. Khosla?s theory of design of foundations for weirs is based on potential theory.
3. Piping problem can be reduced by increasing the length of floor.
4. In Lane?s weighted creep theory, horizontal creep is given less weightage compared to vertical creep.
Which of the above statements is/are correct?
(a) 1
(b) 2, 3 and 4
(c) 2 and 4 only
(d) 3 and 4 only
Ans. (b)
32. The power transmitted through a pipeline is maximum when the head lost due to friction in the pipe is equal to:
(a) the total supply head
(b) half of the total supply head
(c) one-third of the total supply head
(d) one-fourth of the total supply head
Ans. (c)
33. Consider the following with respect to the application of the Navier-Stokes equations:
1. Laminar flown in circular pipes
2. Laminar flow between concentric rotating cylinders
3. Laminar unidirectional flow between stationary parallel plates
4. Laminary unit directional flow between parallel plates having relative motion
Which of the above is/are correct?
(a) 1 only
(b) 2 and 3 only.
(c) 3 and 4 only
(d) 1, 2, 3 and 4
Ans. (c)
34. In a siphon system employed for carrying water from a reservoir A at a higher elevation to another reservoir B at lower elevation, both being separated by a higher hill, what will be the pressure at the ?Summit? (S)?
(a) Equal to the pressure at the water surface of reservoir A
(b) Higher than the pressure at the water surface of reservoir A
(c) Equal to the pressure at the water surface of reservoir B
(d) Less than the pressure at both A and B above
Ans. (d)
35. Consider the following statements related to undersluices provided in diversion weirs on permeable foundations:
I. They are fully gate-controlled and have crest at the same level as the weir crest when no silt excluders are provided.
2. They scour the silt deposited on the river bed in the pockets upstream of the canal head regulator.
3. It is not necessary to provide end pile line on the downstream end of the undersluice floor.
4. The discharge capacity of the undersluice is 10-15% of the maximum flood or two times the maximum discharge of the offtaking canal or maximum winter discharge, whichever is the highest.
Which of the above statements is/are correct?
(a) 1
(b) 2 and 4 only
(c) 2, 3 and 4
(d) 3 and 4 only
Ans. (b)
ONGC Technical-Electronics
ONGC Placement Paper For Electronics
1. Two coils in differential connection have self-inductance of 2 mH and 4 mH and a mutual inductance of 0.15 mH. The equivalent inductance of the combination is
A . 5 .7 mH
B. 5 .85 mH
C. 6 mH
D. 6.1 5 mH.
2. Optocouplers combine
A . SITs and BJTs
B. IGBTs and MOSFETS
C. Power transformers and silicon transistor
D. Infrared light-emitting diode and a silicon phototransistor
3. The difference between the indicated value and the true value of a quantity is known as
A . Gross error
B. Absolute error
C. Dynamic error
D. Relative error
4. The principles of homogeneity and super -position are applied to :
A . linear time variant systems
B. non-linear time variant systems
C. linear time invariant systems
D. non-linear time invariant systems.
5. In a 80 85 microprocessor system with memory mapped I / 0 ,
A. I/0 devices have 8-bit addresses
B. I/0 devices are accessed using IN and OUT instructions
C. there can be a maximum of 2 5 6 input devices and 2 5 6 output devices.
D. arithmetic and logic operations can be directly performed with the I / 0 data.
6. In any transmitting antenna system, efficiency primarily depends upon
A . ohmic losses of various conductors
B. radiation resistance
C. ground conductivity
D. atmospheric conditions.
7. An instruction used to set the carry Flag in a computer can be classified as
A . data transfer
B. arithmetic
C. logical
D. program control
8. The binary representation of 5 .3 7 5 is
A . 1 1 1 .1 0 1 1
B. 1 0 1 .1 1 0 1
C. 1 0 1 .0 1 1
D. 1 1 1 .0 0 1
9. Dislocations in materials are
A . point defect
B. line defect
C. planer defect
D. surface defects.
10. In TV system, vertical pulses are separated out from horizontal pulses by the use of
A . integrator
B. differentiator
C. sweep credit
D. sync separator .
11. Frequency in the UHF range propagate by means of
A . Ground waves
B. Sky waves
C. Surface waves
D. Space waves.
12. 200 MHz may be classified as
A . VHF
B. SHF
C. UHF
D. EHF
13. A communication satellite is a repeater between
A . a transmitting station and a receiving station
B. a transmitting station and many receiving stations
C. many transmitting stations and many receiving stations
D. none of the above
14. The efficiency of a chopper can be expected in the range
A . 5 0 to 5 5 percent
B. 6 5 to 7 2 percent
C. 82 to 87 percent
D. 92 to 99 percent
15. Which one out of the following instruments should be used to measure 6 0 0 kV a.c . voltages?
A . Hot wire instrument
B. Electrostatic voltmeter
C. Moving coil voltmeter
D. Moving iron voltmeter .
16. With reference to figure , value of VCE is
1.0 V
2.5 V
3.-5 V
4. none of the above
17. The smallest change in sound intensity that can be detected
A . 1 dB
B. 3 dB
C. 10 dB
D. 20 dB.
18. In a generic microprocessor , instruction cycle time is
A . shorter than machine cycle time
B. larger than machine cycle time
C. exactly double the machine cycle time
D. exactly the same as the machine cycle time
19. Resistivity of electrical conductors is most affected by
A . temperature
B. pressure
C. composition
D. all of the above .
20. In CCIR B-system of TV , blanking pulse is placed during
A . equalizing pulse
B. retrace interval between each line
C. retrace period of vertical line
D. none of the above .
21. The polarization required in ground wave propagation is
A . Horizontal (linear )
B. vertical (linear )
C. Circular
D. Elliptical
22.Multicavity Klystron
A . is not a microwave device
B. is not a good low level amplifier because of noise
C. is not suitable to pulse operation
D. has a high repeller voltage to insure small transit time
23.Transponder comprises of
A . Transmitter
B. Receiver
C. Antenna
D. a, b , c combined
24.Which of the following regulator provides output voltage polarity reversal without a transformer
A . Buck regulator
B. Boost regulator
C. Buck-boost regulator
D. Cuk regulator
25. The deflection of hot wire instrument depends on
A . RMS value of alternating current
B. voltage
C. average value of a.c . current
D. instantaneous value of a.c . current.
26.Dual slope integration type Analog-to -Digital converters provide
A . higher speeds compared to all other types of A / D converters
B. very good accuracy without putting extreme requirements on component stability
C. poor rejection of power supply hums
D. better resolution compared to all other types of A / D converters for the same number of bits.
27. The frequency modulated (FM) radio frequency range is nearly
A . 2 5 0 – 3 0 0 MHz
B. 1 5 0 – 2 0 0 MHz
C. 9 0 – 1 0 5 MHz
D. 3 0 – 7 0 MHz
28. A 3 2 bit microprocessor has the word length equal to
A . 2 bytes
B. 1 byte
C. 4 bytes
D. 8 bytes
29. Line imperfection in a crystal is called
A . Schottky defect
B. Frenkel defect
C. edge dislocation
D. Miller defect.
30. The function of diplexer bridge in a TV transmitter is
A . to prevent the loading of several transmitters by video transmitter
B. to increase the bandwidth
C. to increase the power output
D. to increase the efficiency of transmission.
31. Sometimes microwave signals follow the earth?s curvature . This due to
A . Ionospheric reflection
B. Faraday rotation
C. Ducting
D. Ionospheric scatter .
32. The modes in a reflex Klystron
A . give the same frequency but different transit time
B. result from excessive transit time across the resonator gap
C. are caused by spurious frequency modulation
D. are just for theoretical considerations.
33. The capacity of a channel is
A . number of digits used in coding
B. volume of information it can take
C. maximum rate of information transmission
D. bandwidth required for information
ONGC Technical-Electronics
ONGC Placement Paper For Electronics
1. Two coils in differential connection have self-inductance of 2 mH and 4 mH and a mutual inductance of 0.15 mH. The equivalent inductance of the combination is
A . 5 .7 mH
B. 5 .85 mH
C. 6 mH
D. 6.1 5 mH.
2. Optocouplers combine
A . SITs and BJTs
B. IGBTs and MOSFETS
C. Power transformers and silicon transistor
D. Infrared light-emitting diode and a silicon phototransistor
3. The difference between the indicated value and the true value of a quantity is known as
A . Gross error
B. Absolute error
C. Dynamic error
D. Relative error
4. The principles of homogeneity and super -position are applied to :
A . linear time variant systems
B. non-linear time variant systems
C. linear time invariant systems
D. non-linear time invariant systems.
5. In a 80 85 microprocessor system with memory mapped I / 0 ,
A. I/0 devices have 8-bit addresses
B. I/0 devices are accessed using IN and OUT instructions
C. there can be a maximum of 2 5 6 input devices and 2 5 6 output devices.
D. arithmetic and logic operations can be directly performed with the I / 0 data.
6. In any transmitting antenna system, efficiency primarily depends upon
A . ohmic losses of various conductors
B. radiation resistance
C. ground conductivity
D. atmospheric conditions.
7. An instruction used to set the carry Flag in a computer can be classified as
A . data transfer
B. arithmetic
C. logical
D. program control
8. The binary representation of 5 .3 7 5 is
A . 1 1 1 .1 0 1 1
B. 1 0 1 .1 1 0 1
C. 1 0 1 .0 1 1
D. 1 1 1 .0 0 1
9. Dislocations in materials are
A . point defect
B. line defect
C. planer defect
D. surface defects.
10. In TV system, vertical pulses are separated out from horizontal pulses by the use of
A . integrator
B. differentiator
C. sweep credit
D. sync separator .
11. Frequency in the UHF range propagate by means of
A . Ground waves
B. Sky waves
C. Surface waves
D. Space waves.
12. 200 MHz may be classified as
A . VHF
B. SHF
C. UHF
D. EHF
13. A communication satellite is a repeater between
A . a transmitting station and a receiving station
B. a transmitting station and many receiving stations
C. many transmitting stations and many receiving stations
D. none of the above
14. The efficiency of a chopper can be expected in the range
A . 5 0 to 5 5 percent
B. 6 5 to 7 2 percent
C. 82 to 87 percent
D. 92 to 99 percent
15. Which one out of the following instruments should be used to measure 6 0 0 kV a.c . voltages?
A . Hot wire instrument
B. Electrostatic voltmeter
C. Moving coil voltmeter
D. Moving iron voltmeter .
16. With reference to figure , value of VCE is
1.0 V
2.5 V
3.-5 V
4. none of the above
17. The smallest change in sound intensity that can be detected
A . 1 dB
B. 3 dB
C. 10 dB
D. 20 dB.
18. In a generic microprocessor , instruction cycle time is
A . shorter than machine cycle time
B. larger than machine cycle time
C. exactly double the machine cycle time
D. exactly the same as the machine cycle time
19. Resistivity of electrical conductors is most affected by
A . temperature
B. pressure
C. composition
D. all of the above .
20. In CCIR B-system of TV , blanking pulse is placed during
A . equalizing pulse
B. retrace interval between each line
C. retrace period of vertical line
D. none of the above .
21. The polarization required in ground wave propagation is
A . Horizontal (linear )
B. vertical (linear )
C. Circular
D. Elliptical
22.Multicavity Klystron
A . is not a microwave device
B. is not a good low level amplifier because of noise
C. is not suitable to pulse operation
D. has a high repeller voltage to insure small transit time
23.Transponder comprises of
A . Transmitter
B. Receiver
C. Antenna
D. a, b , c combined
24.Which of the following regulator provides output voltage polarity reversal without a transformer
A . Buck regulator
B. Boost regulator
C. Buck-boost regulator
D. Cuk regulator
25. The deflection of hot wire instrument depends on
A . RMS value of alternating current
B. voltage
C. average value of a.c . current
D. instantaneous value of a.c . current.
26.Dual slope integration type Analog-to -Digital converters provide
A . higher speeds compared to all other types of A / D converters
B. very good accuracy without putting extreme requirements on component stability
C. poor rejection of power supply hums
D. better resolution compared to all other types of A / D converters for the same number of bits.
27. The frequency modulated (FM) radio frequency range is nearly
A . 2 5 0 – 3 0 0 MHz
B. 1 5 0 – 2 0 0 MHz
C. 9 0 – 1 0 5 MHz
D. 3 0 – 7 0 MHz
28. A 3 2 bit microprocessor has the word length equal to
A . 2 bytes
B. 1 byte
C. 4 bytes
D. 8 bytes
29. Line imperfection in a crystal is called
A . Schottky defect
B. Frenkel defect
C. edge dislocation
D. Miller defect.
30. The function of diplexer bridge in a TV transmitter is
A . to prevent the loading of several transmitters by video transmitter
B. to increase the bandwidth
C. to increase the power output
D. to increase the efficiency of transmission.
31. Sometimes microwave signals follow the earth?s curvature . This due to
A . Ionospheric reflection
B. Faraday rotation
C. Ducting
D. Ionospheric scatter .
32. The modes in a reflex Klystron
A . give the same frequency but different transit time
B. result from excessive transit time across the resonator gap
C. are caused by spurious frequency modulation
D. are just for theoretical considerations.
33. The capacity of a channel is
A . number of digits used in coding
B. volume of information it can take
C. maximum rate of information transmission
D. bandwidth required for information
ONGC Latest Mechanical Placement paper Questions
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SECTION 1-MECHANICAL
1 During the execution of a CNC part program block NO20 GO2 X45.0 Y25.0 R5.0 the type of tool motion will be
A) circular Interpolation — clockwise
B) circular Interpolation — counterclockwise
C) linear Interpolation
D) rapid feed
Answer : (A)
2 A component can be produced by any of the four processes I, II, III and IV. Process I has a fixed cost ofRs. 20 and variable cost of Rs. 3 per piece. Process II has a fixed cost Rs. 50 and variable cost of Re. 1 per piece. Process III has a fixed cost of Rs. 40 and variable cost of Rs. 2 per piece. Process IV has a fixed cost of Rs. 10 and variable cost of Rs. 4 per piece. If the company wishes to produce 100 pieces of the component, from economic point of view it should choose
A) Process I
B) Process II
C) Process III
D) Process IV
Answer : (B)
3 In an interchangeable assembly, shafts of size 25.000+0.040mm mate with holes of size 25.000+0.020 mm. The maximum possible clearance in the assembly will be
A) 10 microns
B) 20 microns
C) 30 microns
D) 60 microns
Answer : (D)
4 A company has two factories S1, S2 and two warehouses D1, D2. The supplies from S1 and S2 are 50 and 40 units respectively. Warehouse D1 requires a minimum of 20 units and a maximum of 40 units. Warehouse D2 requires a minimum of 20 units and, over and above, it can take as much as can be supplied. A balanced transportation problem is to be formulated for the above situation. The number of supply points, the number of demand points, and the total supply (or total demand) in the balanced transportation problem respectively are
A) 2, 4, 90
B) 2, 4, 110
C) 3, 4, 90
D) 3, 4, 110
Answer : (C)
5 An incompressible fluid (kinematic viscosity, 7.4 x 10-7 m2/s, specific gravity, 0.88) is held between two parallel plates. If the top plate is moved with a velocity of 0.5 m/s while the bottom one is held stationary, the fluid attains a linear velocity profile in the gap of 0.5 mm between these plates; the shear stress in Pascals on the surface of top plate is
A) 0.651 x 10-3
B) 0.651
C) 6.51
D) 0.651 x 103
Answer : (B)
6 The tool of an NC machine has to move along a circular arc from (5,5) to (10,10) while performing an operation. The centre of the arc is at (10,5). Which one of the following NC tool path commands performs the above mentioned operation?
A) N010 G02 X10 Y10 X5 Y5 R5
B) N010 G03 X10 Y10 X5 Y5 R5
C) N010 G01 X5 Y5 X10 Y10 R5
D) N010 G02 X5 Y5 X10 Y10 R5
Answer : (D)
7 During a Morse test on a 4 cylinder engine, the following measurements of brake power were taken at constant speed.
All cylinders firing 3037 kW
Number 1 cylinder not firing 2102 kW
Number 2 cylinder not firing 2102 kW
Number 3 cylinder not firing 2100 kW
Number 4 cylinder not firing 2098 kW
The mechanical efficiency of the engine is
A) 91.53%
B) 85.07%
C) 81.07%
D) 61.22%
Answer : (C)
8 In terms of theoretical stress concentration factor (Kt) and fatigue stress concentration factor (Kf ), the notch sensitivity ‘q’ is expressed as
A) (Kf -1) (Kt -1)
B) (Kf -1) (Kt +1)
C) (Kt -1) (Kf -1)
D) (Kf +1) (Kt +1)
Answer : (A)
9 Starting from x0 = 1, one step of Newton-Raphson method in solving the equation x3 + 3x -7 = 0 gives the next value (x1) as
A) x1 = 0.5
B) x1= 1.406
C) x1= 1.5
D) x1 = 2
Answer : (C)
10 The S-N curve for steel becomes asymptotic nearly at
A) 103 cycles
B) 104 cycles
C) 10 6 cycles
D) 10 9 cycles
Answer : (C)
11. In PERT analysis a critical activity has
A) maximum Float
B) zero Float
C) maximum Cost
D) minimum Cost
Answer : (B)
12 Environment friendly refrigerant R134a is used inthe new generation domestic refrigerators. Itschemical formula is
A) CH C1 F2
B) C2 C13 F3
C) C2 C12 F4
D) C2 H2 F4
Answer : (D)
13 A solid cylinder (surface 2) is located at the centreof a hollow sphere (surface 1). The diameter of the sphere is 1m, while the cylinder has a diameter and length of 0.5 m each. The radiation configuration factor F11 is
A) 0.375
B) 0.625
C) 0.75
D) 1
Answer : (C)
14 For a fluid flow through a divergent pipe of length L having inlet and outlet radii of R1 and R2 respectively and a constant flow rate of Q, assuming the velocity to be axial and uniform at any cross-section, the acceleration at the exit is
A) 2Q(R1 – R2) p LR23
B) 2Q2 (R1 – R2) p LR23
C) 2Q2 (R1 – R2) p2LR25
D) 2Q2 (R2 – R1) p2LR25
Answer : (C)
15 An incompressible fluid (kinematic viscosity, 7.4 x 10-7 m2/s, specific gravity, 0.88) is held between two parallel plates. If the top plate is moved with a velocity of 0.5 m/s while the bottom one is held stationary, the fluid attains a linear velocity profile in the gap of 0.5 mm between these plates; the shear stress in Pascals on the surface of top plate is
A) 0.651 x 10-3
B) 0.651
C) 6.51
D) 0.651 x 103
Answer : (B)
16 The tool of an NC machine has to move along a circular arc from (5,5) to (10,10) while performing an operation. The centre of the arc is at (10,5). Which one of the following NC tool path commands performs the above mentioned operation?
A) N010 G02 X10 Y10 X5 Y5 R5
B) N010 G03 X10 Y10 X5 Y5 R5
C) N010 G01 X5 Y5 X10 Y10 R5
D) N010 G02 X5 Y5 X10 Y10 R5
Answer : (D)
17 During a Morse test on a 4 cylinder engine, the following measurements of brake power were taken at constant speed.
All cylinders firing 3037 kW
Number 1 cylinder not firing 2102 kW
Number 2 cylinder not firing 2102 kW
Number 3 cylinder not firing 2100 kW
Number 4 cylinder not firing 2098 kW
The mechanical efficiency of the engine is
A) 91.53%
B) 85.07%
C) 81.07%
D) 61.22%
Answer : (C)
18 In terms of theoretical stress concentration factor(Kt) and fatigue stress concentration factor (Kf ), the notch sensitivity ‘q’ is expressed as
A) (Kf -1) (Kt -1)
B) (Kf -1) (Kt +1)
C) (Kt -1) (Kf -1)
D) (Kf +1) (Kt +1)
Answer : (A)
19 Starting from x0 = 1, one step of Newton-Raphson method in solving the equation x3 + 3x -7 = 0 gives the next value (x1) as
A) x1 = 0.5
B) x1= 1.406
C) x1= 1.5
D) x1 = 2
Answer : (C)
20 A maintenance service facility has Poisson arrival rates, negative exponential service time and operates on a ‘first come first served’ queue discipline. Break downs occur on an average of 3 per day with a range of zero to eight. The maintenance crew can service an average of 6 machines per day with a range of zero to seven. The mean waiting time for an item to be serviced would be
A) 16 day
B) 13 day
C) 1 day
D) 3 days
Answer : (A)
21 The S-N curve for steel becomes asymptotic nearly at
A) 103 cycles
B) 104 cycles
C) 106 cycles
D) 109 cycles
Answer : (C)
22 In a rolling process, sheet of 25 mm thickness is rolled to 20 mm thickness. Roll is of diameter 600 mm and it rotates at 100 rpm. The roll strip contact length will be
A) 5 mm
B) 39 mm
C) 78mm
D) 120mm
Answer : (A)
23 Water at 42°C is sprayed into a stream of air at atmospheric pressure, dry bulb temperature of 40°C and a wet bulb temperature of 20°C. The air leaving the spray humidifier is not saturated. Which of the following statements is true?
A) Air gets cooled and humidified
B) Air gets heated and humidified
C) Air gets heated and dehumidified
D) Air gets cooled and dehumidified
Answer : (B)
24 The angle between two unit-magnitude coplanar vectors P(0.866, 0.500,0) and Q(0.259, 0.966,0) will be
A) 0°
B) -30°
C) 45°
D) 60°
Answer : (C)
25 A lot has 10% defective items. Ten items are chosen randomly from this lot. The probability that exactly 2 of the chosen items are defective is
A) 0.0036
B) 0.1937
C) 0.2234
D) 0.3874
Answer : (B)
26 Stokes theorem connects
A) a line integral and a surface integral
B) a surface integral and a volume integral
C) a line integral and a volume integral
D) gradient of a function and its surface integral
Answer : (A)
27 A solar collector receiving solar radiation at the rate of 0.6 k W/m2 transforms it to the internal energy of a fluid at an overall efficiency of 50%. The fluid heated to 350 K is used to run a heat engine which rejects heat at 313 K. If the heat engine is to deliver 2.5 kW power, the minimum area of the solar collector required would be
A) 8.33m2
B) 16.66m2
C) 39.68m2
D) 79.36m2
Answer : (D)
28 When the temperature of a solid metal increases,
A) strength of the metal decreaes but ductility increases
B) both strength and ductility of the metal decrease
C) both strength and ductility of the metal increase
D) strength of the metal increases but ductility decreases
Answer : (A)
29 A company produces two types of toys: P and Q. Production time of Q is twice that of P and the company has a maximum of 2000 time units per day. The supply of raw material is just sufficient to produce 1500 toys (of any type) per day. Toy type Q requires an electric switch which is available @ 600 pieces per day only. The company makes a profit of Rs. 3 and Rs. 5 on type P and Q respectively. For maximization of profits, the daily production quantities of P and Q toys should respectively be
A) 100, 500
B) 500, 1000
C) 800, 600
D) 1000, 1000
Answer : (C)
30 A spherical thermocouple junction of diameter 0.706 mm is to be used for the measurement Aof temperature of a gas stream. The convective heat transfer co-efficient on the bead surface is 400 W/m2K. Thermophysical properties of thermocouple material are k = 20 W/mK, C = 400 J/kg K and r = 8500 kg/m3. If the thermocouple initially tot 30°C is placed in a hot stream of 300°C, the time taken by the bead to reach 298°C, is
A) 2.35 s
B) 4.9 s
C) 14.7 s
D) 29.4 s
Answer : (B)
31 In a spring-mass system, the mass is 0.1 kg and the stiffness of the spring is 1 kN/m. By introducing a damper, the frequency of oscillation is found to be 90% of the original value. What is the damping coefficient of the damper?
A) 1.2 N.s/m
B) 3.4 N.s/m
C) 8.7 N.s/m
D) 12.0 N.s/m
Answer : (C)
32.In a machining operation, doubling the cutting speed reduces the tool life to 1/8 of the original value. The exponent n in Taylor
A) 1/8
B) 1/4
C) 1/3
D) 1/2
Answer : (C)
33.In a rolling process, sheet of 25 mm thickness is rolled to 20 mm thickness. Roll is of diameter 600 mm and it rotates at 100 rpm. The roll strip contact length will be
A) 5 mm
B) 39 mm
C) 78 mm
D) 120 mm
Answer : (A)
34.A soldering operation was work-sampled over two days (16 hours) during which an employee soldered 108 joints. Actual working time was 90% of the total time and the performance rating was estimated to be 120 percent. If the contract provides allowance of 20 percent of the total time available, the standard time for the operation would be
A) 8 min
B) 8.9 min
C) 10 min
D) 12 min
Answer : (D)
35. A welding operation is time-studied during which an operator was pace-rated as 120%. The operator took, on an average, 8 minutes for producing the weld-joint. If a total of 10% allowances are allowed for this operation, the expected standard production rate of the weld-joint (in units per 8 hour day) is
A) 45
B) 50
C) 55
D) 60
Answer : (A)
36. In PERT analysis a critical activity has
A) maximum Float
B) zero Float
C) maximum Cost
D) minimum Cost
Answer : (B)
37.Environment friendly refrigerant R134a is used in the new generation domestic refrigerators. Its chemical formula is
A) CH C1 F2
B) C2 C13 F3
C) C2 C12 F4
D) C2 H2 F4
Answer : (D)
38. The parabolic arc y = x, 1 = x = 2 is revolved around the x-axis. The volume of the solid of revolution is
(A)4 p (B) 2 p (C) 3 4 p (D) 3 2
39. A moist air sample has dry bulb temperature of 30ºC and specific humidity of 11.5g water vapour per kg dry air. Assume molecular weight of air as 28.93. If
the saturation vapour pressure of water at 30ºC is 4.24kPa and the total pressure is 90kPa, then the relative humidity (in %) of air sample is
(A) 50.5 (B) 38.5 (C) 56.5 (D) 68.5
40. The value of the integral 2 dx 1 x 8 -8 + ? is
(A) -p (B) 2 p (C) 2 p (D) p
41. The modulus of the complex number 3 4i 1 2i ? + ? ? – ? ? ? is
(A) 5 (B) 5 (C)15(D)15
42. The function y = 2 – 3x
(A) is continuous ?x ? R and differentiable ?x ? R
(B) is continuous ?x ? R and differentiable ?x ? R except at x=3/2
(C) is continuous ?x ? R and differentiable ?x ? R except at x=2/3
(D) is continuous ?x ? R except at x=3 and differentiable ?x ? R
6. Mobility of a statically indeterminate structure is
(A) = -1 (B) 0 (C) 1 (D) = 2
43. There are two points P and Q on a planar rigid body. The relative velocity between the two points
(A) should always be along PQ
(B) Can be oriented along any direction
(C) should always be perpendicular to PQ
(D) should be along QP when the body undergoes pure translation
44. The state of plane-stress at a point is given by sx = -200MPa, sy = 100MPa and txy = 100MPa. The maximum shear stress in MPa is
(A) 111.8 (B) 150.1 (C) 180.3 (D) 223.6
45. Which of the following statements is INCORRECT?
(A) Grashof’s rule states that for a planar crank-rocker four bar mechanism, the sum of the shortest and longest link lengths cannot be less than the sum of the remaining two link lengths.
(B) Inversions of a mechanism are created by fixing different links one at a time.
(C) Geneva mechanism is an intermittent motion device
(D) Gruebler’s criterion assumes mobility of a planar mechanism to be one.
46. The natural frequency of a spring-mass system on earth is ?n. The natural frequency of this system on the moon (gmoon = gearth / 6) is
(A) ?n (B)0.408?n (C) 0.204?n (D) 0.167?n
47. Tooth interference in an external involute spur gear pair can be reduced by
(A) decreasing center distance between gear pair
(B) decreasing module
(C) decreasing pressure angle
(D) increasing number of gear teeth
48. For the stability of a floating body, under the influence of gravity alone, which of the following is TRUE?
(A) Metacentre should be below centre of gravity
(B) Metacentre should be above centre of gravity
(C) Metacentre and centre of gravity must lie on the same horizontal line
(D) Metacentre and centre of gravity must lie on the same vertical line
49. The maximum velocity of a one-dimensional incompressible fully developed viscous flow, between two fixed parallel plates, is 6ms-1. The mean velocity (in ms-1) of the flow is
(A) 2 (B) 3 (C) 4 (D) 5
50. A phenomenon is modeled using n dimensional variables with k primary dimensions. The number of non-dimensional variables is
(A) k (B) n (C) n-k (D) n+k
51. A turbo-charged four-stroke direct injection diesel engine has a displacement volume of 0.0259m3 (25.9litres) . The engine has an output of 950kW at 2200rpm. The mean effective pressure in MPa is closest to
(A) 2 (B) 1 (C) 0.2 (D) 0.1
52. One kilogram of water at room temperature is brought into contact with a high temperature thermal reservoir. The entropy change of the universe is
(A) equal to entropy change of the reservoir
(B) equal to entropy change of water
(C) equal to zero
(D) always positive
53. A hydraulic turbine develops 1000kW power for a head of 40m. If the head is reduced to 20m, the power developed (in kW) is
(A) 177 (B) 354 (C) 500 (D) 707
54. The material property which depends only on the basic crystal structure is
(A) fatigue strength (B) work hardening (C) fracture strength (D) elastic constant
55. In a gating system, the ratio 1:2:4 represents
(A) sprue base area: runner area: ingate area
(B) pouring basin area: ingate area: runner area
(C) sprue base area: ingate area: casting area
(D) runner area: ingate area: casting area
56. A shaft has a dimension, 0.009 .025 — f . The respective values of fundamental deviation and tolerance are
(A) -0.025, ± 0.008 (B) -0.025,0.016
(C) -0.009, ±0.008 (D) -0.009,0.016
57. In a CNC program block, N002 G02 G91 X40 Z40…, G02 AND G91 refer to
(A) circular interpolation in counterclockwise direction and incremental dimension
(B) circular interpolation in counterclockwise direction and absolute dimension
(C) circular interpolation in clockwise direction and incremental dimension
(D) circular interpolation in clockwise direction and absolute dimension
58. The demand and forecast for February are 12000 and 10275, respectively. Using single exponential smoothening method (smoothening coefficient = 0.25), forecast for the month of March is
(A) 431 (B) 9587 (C) 10706 (D) 11000
59. Little’s law is relationship between
(A) stock level and lead time in an inventory system
(B) waiting time and length of the queue in a queuing system
(C) number of machines and job due dates in a scheduling problem
(D) uncertainty in the activity time and project completion time
60. Vehicle manufacturing assembly line is an example of
(A) product layout (B) process layout (C) manual layout (D) fixed layout
61. Simplex method of solving linear programming problem uses
(A) all the points in the feasible region
(B) only the corner points of the feasible region
(C) intermediate points within the infeasible region
(D) only the interior points in the feasible region.
62. Torque exerted on a flywheel over a cycle is listed in the table. Flywheel energy (in J per unit cycle) using Simpson’s rule is Angle (degree) 0 60 120 180 240 300 360Torque (Nm) 0 1066 -323 0 323 -355 0
(A) 542 (B) 993 (C) 1444 (D) 1986
63. A lightly loaded full journal bearing has a journal of 50mm, bush bore of 50.05mm and bush length of 20mm. if rotational speed of journal is 1200rpmand average viscosity of liquid lubricant is 0.03 Pa s, the power loss (in W) will be
(A) 37 (B) 74 (C) 118 (D) 23
ONGC Question Bank in Computer Science for practice This is only model questions for practice
Multiple Choice Questions
1. A computer derives its basic strength from
(a) speed
(b) accuracy
(c) memory
(d) all of the above (Ans)
(e) None of the above.
2. Modern computers compared to earlier computers are
(a) faster and larger
(b) less reliable
(c) larger and stronger
(d) slower but more reliable
(e) faster and smaller (Ans)
3. The use of computer for business applications is attractive because of its
(a) accuracy
(b) reliability
(c) speed
(d) secret code facility
(e) All of the above (Ans)
4. A computer is capable of performing almost any task, provided that it can be
(a) coded
(b) memorized
(c) analyzed
(d) reduced to a series of logical steps (Ans)
(e) changed top mathematics equation
5. A BIT represents a
(a) decimal digit
(b) octal digit
(c) binary digit (Ans)
(d) hexa decimal digit
6. A computer has very high speed, accuracy and reliability. Its intelligence quotient could be of the order of
(a) 100
(b) 0 (Ans)
(c) 50
(d) 200
(e) 99.99
7. Computer can not do anything without a
(a) chip
(b) memory
(c) output device
(d) program (Ans)
(e) None of the above
8. A computer possesses information
(a) as directed by the operator
(b) automatically (Ans)
(c) at once
(d) gradually and eventually
(e) by truncating
9. Pick up the false statement
(a) computer can manipulate both numeric and non-numeric symbols
(b) computer errors can usually be traced to faulty programs or inaccurate input data
(c) the facts or informational raw materials represented by numeric and non-numeric symbols are called information (Ans)
(d) the space in the primary storage section is divided into four areas: input, working, storage, output and program storage.
(e) Information is the relevant knowledge that results from the processing and arranging of data in an ordered and useful form.
10. Processors of all computers, whether micro, mini or mainframe must have
(a) ALU
(b) primary storage
(c) control Unit
(d) all of the above (Ans)
(e) None of the above.
11. Pick up the correct statement about computers
(a) computers process data with human intervention after the program has been fed
(b) all comparisons are made in the control section
(c) the arithmetic-logic section of the CPU selects, interprets and executes the program steps.
(d) the secondary storage devices are usually connected on line to the CPU but for accepting data from them or returning data to them, human intervention is required
(e) computers have the built-in ability to obey different types of instructions. (Ans)
12. Real time computing is possible because of the following characteristic of computer
(a) storage capability
(b) high speed (Ans)
(c) accuracy
(d) versatility
(e) automatic in execution
13. Pick out the wrong statement about modern computer systems
(a) these are simple and easy to take care of
(b) even beginners, untrained persons can safely handle them (Ans)
(c) they require a highly disciplined approach
(d) it is important to understand the proper overall procedures must be followed
(e) the negligent use of a computer system will almost always introduce time bombs into the system.
14. A collection of eight bits is called:
(a) byte (Ans)
(b) word
(c) record
(d) file
(e) None of the above
15. Choose the incorrect statement about micro computers, mini-computers, etc.
(a) a microcomputer can be placed on a single silicon chip
(b) a minicomputer can have more processing capability than a mainframe model
(c) a microcomputer chip performs the arithmetic-logic and control functions of a microcomputer
(d) ROM chips may be used in micros ;to permanently store program instruction
(e) most micros use rigid disk storage devices rather than floppy disk drives. (Ans)
16. Control Unit of a digital computer is often called the
(a) lock
(b) nerve center (Ans)
(c) ICs
(d) all of the above
(e) None of the above
17. Pick up the correct statement
(a) most mainframes are 48-bit machines
(b) thousands of super computers are currently being built
(c) super-computers are usually designed to process accounting applications
(d) mainframes may have multi-processor components that permit several tasks to be processed at the same instant in time (Ans)
(e) minicomputers can not use high speed buffer storage components and are thus always slower than mainframe models.
18. The following acronym recognizes the fact that “computer errors” can usually be traced to incorrect input data or unreliable programs
(a) IGO (Ans)
(b) FIFO
(c) LIFO
(d) DASD
(e) ROM
19. Group of instructions that directs a computer is called
(a) storage
(b) memory (Ans)
(c) logic
(d) program
(e) None of the above
20. Which of the following does not describe one or more characteristics of a computer?
(a) electronic
(b) external storage
(c) stored program
(d) program modification at execution (Ans)
(e) All of the above are characteristics.
21. Which of the following statements is true?
(a) the smart approach to using computers is to write programs
(b) knowledge of the system development life cycle is not important to operators who use computers without programming
(c) hands-on exposure to the computer is not helpful to those who write programs
(d) personal computer have been an important contributing factor in the movement towards using computers without programming (Ans)
(e) None of the above is true
22. Which can read data and convert them to a form that a computer can use?
(a) logic
(b) storage
(c) control
(d) input device (Ans)
(e) output device
23. Software instruction intended to satisfy a user’s specific processing needs are called
(a) system software
(b) a microcomputer
(c) documentation
(d) applications software (Ans)
(e) All of the above
24. Which kind of hardware is used the most in the input phase of a computer based information system?
(a) keyboard (Ans)
(b) printer
(c) monitor
(d) hard disk
(e) floppy disk
25. Which of the following is not a factor when categorizing a computer
(a) amount of main memory the CPU can use
(b) capacity of the storage devices
(c) cost of the system
(d) where it was purchased (Ans)
(e) speed of the output device
26. Which of the following is the most powerful type of computer?
(a) super micro
(b) super conductor
(c) microcomputer
(d) super computer (Ans)
(e) megaframe
27. Which of the following people probably has the least amount of technical knowledge ?
(a) programmer
(b) user (Ans)
(c) system analyst
(d) computer operator
(e) computer professional
28. Which kind of storage device cab be carried around?
(a) floppy disk (Ans)
(b) hard disk
(c) system cabinet
(d) hard disk drive
(e) floppy disk drive
29. Which of the following terms applies to communication between separate computer systems?
(a) computer literacy
(b) power supply
(c) applications software
(d) connectivity (Ans)
(e) None of the above
30. The Central Processing Unit (CPU) consists of:
(a) input, output and processing
(b) control unit, primary storage & secondary storage
(c) control unit, arithmetic-logic unit, primary storage (Ans)
(d) control unit, processing, primary storage
(e) None of the above
31. People typically interface with a computer based system when:
(a) information must be output
(b) data must be input
(c) information must be reviewed the computer needs a direction (or instruction) in order to process data
(d) All of the above
(Ans : e)
32. The principle advantage of the centralized approach to organizing a computer facility is :
(a) cost-effectiveness
(b) processing activities are easier to coordinate
(c) Processing activities are easier to control
(d) processing statements can be enforced
(e) All of the above (Ans)
33. The fifth generation digital computer will be
(a) extremely low cost
(b) very expensive
(c) versatility
(d) artificial intelligence (Ans)
(e) None of the above
34. To be information, data must be
(a) factual
(b) relevant
(c) news
(d) all of the above (Ans)
(e) None of the above
35. A data system for calculating measures used in statistical inference is an example of a
(a) teleprocessing system
(b) data management system
(c) computing system (Ans)
(d) All of the above
(e) None of the above
36. For the purposes of defining data needs, a responsibility area is
(a) marketing
(b) administration
(c) personal (Ans)
(d) all of the above
(e) None of the above
37. Which is widely used in academic testing?
(a) MICR
(b) POS
(c) OCR
(d) OMR (Ans)
(e) None of the above
38. Coded entries which are used to gain access to a computer system are called:
(a) entry codes
(b) passwords (Ans)
(c) security commands
(d) code words
39. A factor which might cause an individual to consider using a computer in criminal activities is :
(a) the computer’s access to large sums to money
(b) the speed with which the crime can be accomplished
(c) EFTS (Electronic Funds Transfer System)
(d) All of the above (Ans)
40. EBCDIC can code up to how may different characters ?
(a) 816
(b) 32
(c) 64
(d) 256
(Ans : e)
41. Which of the following statements is true?
(a) the installation of a computer is favorably received by all employees
(b) some form of training is necessary for employees who will work with computers (Ans)
(c) computers are portrayed solely as society’s benefactor
(d) a business person is only interested in the computer’s accuracy.
42. Which is considered a direct entry input device?
(a) optical scanner
(b) mouse
(c) light pen
(d) digitizer
(e) All of the above (Ans)
43. The daily processing of corrections to customer accounts best exemplifies the processing mode of :
(a) batch processing (Ans)
(b) real-time processing
(c) interactive processing
(d) All of the above
44. The data processing job expected to further decreases in the 1990s is that of :
(a) keypuncher (Ans)
(b) data entry clerk
(c) computer operator
(d) programmer
45. Which is a unit of measurement used with computer systems?
(a) byte
(b) kilobyte
(c) megabyte
(d) gigabyte
(e) All of the above (Ans)
46. Which of the following statements is true?
(a) analysts usually work alone and sometimes as part of a team
(b) most systems projects are completed in 6 12 weeks
(c) an analyst’s primary concern is the development of software
(d) analysts evaluate data flow through an organization (Ans)
47. In computer terminology, information means
(a) raw data
(b) data in more useful or intelligible form (Ans)
(c) alphanumeric data
(d) program
48. A computer programmer
(a) does all the thinking for a computer (Ans)
(b) can enter input data quickly
(c) can operate all types of computer equipment
(d) can draw only flowchart
49. A character is represented in EBCDIC by:
(a) one bit
(b) four bits
(c) eight bits (Ans)
(d) sixteen bits
(e) None of the above
50. Most of the errors blamed on computers are actually due to
(a) programming errors
(b) hardware fatique
(c) defects in floppy disks
(d) data entry errors (Ans)
51. Which is a secondary memory device ?
(a) CPU
(b) ALU
(c) Floppy disk (Ans)
(d) Mouse
(e) None of the above
52. Which is the most significant difference between a simple desk calculator and computer? Choose from the following (note that some of the following may not even be true).
(a) the computer is an electronic machine while the desk calculator may or may not be electronic
(b) the computer is useful in business applications while the desk calculator is not
(c) the computer can print its results, while the desk calculator can only show it on a display
(d) the computer is controlled by a program stored in its memory while calculator require step-by-step manual control (Ans)
(e) One has to know the method of calculation while using a calculator but a computer user can depend upon the computer to choose the method automatically.
53. A term associated with the comparison of processing speeds of different computer systems is :
(a) EFTS
(b) MPG
(c) MIPS (Ans)
(d) CPS
54. RAM is used as a short memory beacuse it
(a) is volatile (Ans)
(b) is very expensive
(c) has small capacity
(d) is programmable
(e) None of the above
55. General purpose computes are those that can be adopted to countless uses simply by changing its.
(a) keyboard
(b) printer
(c) program (Ans)
(d) display screen
(e) None of the above
56. Which is the computer memory that does not forget?
(a) ROM (Ans)
(b) RAM
(c) PROM
(d) All of the above
(e) None of the above
57. The Senta Clara Valley near Palo Alto, California is popularly known as Silicon Valley of America because
(a) huge deposits of silicon are found there
(b) many silicon chip manufacturing firms are located there (Ans)
(c) Santa Claus visits it every Christmas
(d) it is full of large grain sand
58. Computers are incapable of emotional feelings. However, some people attribute humanlike emotions to imitate objects including computers. What is it called?
(a) anthropogenesis
(b) anthropomorphism (Ans)
(c) anthroolatory
(d) cybernetics
59. According to you, which of the following statements is incorrect?
(a) generally, computers don’t make mistakes
(b) computers eliminate jobs
(c) computers can think (Ans)
(d) maths is necessary to understand computers
60. The most common binary code in use today is the 8 bit ASCII code. What do the letters ASCII stand for?
(a) American Standard Code for International Interchange
(b) American Standard Code for Information Interchange (Ans)
(c) American Standard Code for Intelligence interchange
(d) American Scientific Code for Information Interchange
(e) None of the above
Placement Paper
ONGC general awareness questions with answers
1) As per the data released in March 2012,India exports registered how much growth in January 2012 at $25.34 billion with the demand from the western markets remaining weak?
1) 10.1 Percent
2) 8.4 Percent
3) 9.8 Percent
4) 12.2 Percent
2) The union cabinet on march 1,2012 approved the proposal to bring down the quantum of subsidy on decontrolled fertilizers fro 2012-13.Which of the following are those fertilizers?
1) Phosphatic (P)
2) Potassic (K)
3) Nitrogenous (N)
4) Only 1 and 2
3) in an innovative mechanism to partally make up for the short fall in the disinvestment target set for the current fiscal,the union cabinet in March 2012 approved buy-back of the centre’s equity by cash-rich public sector undertakings.what was the target ?
1) Rs 20,000 Crore
2) Rs 30,000 Crore
3) Rs 40,000 Crore
4) Rs 50,000 Crore
4) A commerce ministry statement in march 2012 showed that imports of sensitive items,went up by 44.7 percent to Rs 75,948 Crore in April-Dec. 2011 from Rs 52,492 Crore in the year ago period.which items are in reference here?
1) Fruits
2) Vegetable
3) Edible oils
4) All of the above
5) Spice Jet on March 2, 2012 said its promoters agreed to infuse Rs 100 Crore fresh funds into the airline in exchange for an additional equity of 42.9 million shares,aggregating to
1) 5 percent
2) 10 percent
3) 15 percent
4) 20 percent
6) The directorate general of foreign trade(DGFT) issued a notification in March 2012 prohibiting export of which of the following commodities with immediate effect?
1) Onion
2) Sugar
3) Cotton
4) Pulses
7) Global mining giant Rio Tinto announced Plans to invest $ 2 billion in iron ore and diamond mining projects in Madhya Pradesh and
1) Rajasthan
2) Orissa
3) West Bengal
4) Jharkhand
8) Which of the following in March 2012 joined hands to set up India’s first $2 billion infra structure Debt. Funds(IDF)?
1) ICICI Bank
2) Citi Finanacial
3) Bank of Baroda and life Insurance Corporation
4) All of the above
9) The PMO office in March 2012 stepped in to the fast track the development and use of inland water transport(IWT) which opens the water route for movement of bulk cargo such as
1) Coal
2) Food grains
3) fertilizers
4) All of the above
10) During Feb. 2012 Indian companies invested around how much abroad with reliance industries Ltd. and Tata Sons emerging as major investors?
1) $ 1.01 billion
2) $ 2.01 billion
3) $ 3.01 billion
4) $ 4.01 billion
11) The RBI on March 9,2012 reduced the cash Reserve Ratio(CRR) by how many basis points with effect from March 10,2012 ?
1) 25 points
2) 50 points
3) 75 points
4) 100 points
12) As per the data released in March 2012, imports grew at a faster rate year-on-year at $39.8 billion, Translator into a trade deficit of $15.2 billion during the month.What was the % of this faster rate?
1) 12.4 Percent
2) 16.2 Percent
3) 20.6 Percent
4) 26.8 Percent
13) Ranbaxy Laboratory in March 2012 announced the opening of its new production facility in which African countries,which would help it access the African nation $1 billion pharmaceutical market ?
1) Morocco
2) Rwanda
3) republic of Congo
4) Botswana
14) Telecom company Etisalat, in March 2012 announced to have started proceedings for winding up operations of its Indian venture. Etisalat is based in which of the following countries ?
1) UAE
2) Saudi Arabia
3) Malaysia
4) Iran
15) The International Air Transport (IATA) in March 2012 urged the Indian Govt. to address which of the following issues to remove the shackles of the available sector?
1) High Fuel tax
2) High Service Tax
3) Cost and Infrastructure
4) All of the above
16) In a major relief to the airlines industry, the union Budget 2012-13 presented in the Parliament on March 16,2012, proposed to allow it to raise funds through external commercial borrowings worth how much for a year?
1) $1 billion
2) $2 billion
3) $5 billion
4) $10 billion
17) Giving Push to the infrastructure sector in the budget, Finance minister Pranab Mukherjee, in March 2012 allowed financial institutions to raise about how much from Tax-free bonds and opening decks for larger private participation ?
1) Rs 30,000 crore
2) Rs 50,000 crore
3) Rs 60,000 crore
4) Rs 75000 crore
18) Which bank in March 2012 announced its share holders to have approved Rs 7900 crore capital infusion by the government?
1) Punjab National Bank
2) Indian overseas Bank
3) State Bank India
4) Oriental bank of commerce
19) Tata Motors owned Jaguar Land Rover 2012 ti have finalized cherry Automobile company as partner to form an equal Joint Venture ?
1) Japan
2) Brazil
3) China
4) South Africa
20) In a significant move The Reserve Bank of India in March 2012 tightened the rules for lending against —– jewellery by Non- Banking finance company (NBFC’s)
1) Diamond
2) Gold
3) Silver
4) All of the above
21) The Fifth Edition of the World Future Energy Summit was held in
a) Abu Dhabi
b) New Delhi
c) Tehran
d) Dhaka
Ans a
22) Planning Commission of India on January 18,2012 approved Rudrasagar development scheme.The Scheme is related to
a) Tripura
b) Assam
c) Manipur
d) Sikkim
Ans a
23) The Board of approval (BoA) under the Commerce ministry on January 24,2012 approved the proposal of this company to set up a special economics zone( SEZ) at Indore in Madhya Pradesh, Identify the Company ?
a) Reliance Industry
b) Tata Consultancy services( TCS)
c) Hero Motors
d) Infoysys
Ans b
24) Scientists identified a new gene in maize Plants called ?
a) Meg 1
b) Meg 2
c) Meg 3
4) Meg 4
Ans a
25) Researches discovered new earthworm species in Port Blair. What is the name of the new Species ?
a) Moniligaster ivaniosi
b) Annelida
c) Nematoda
d) Onychophora
Ans a
26) Scientists recently developed a new wireless device to detect the Presence of termites. Consider the following statement-
1) when the new device detects the presence of termites,it sends an SMS or email to a pest Control firm.
2) The Device is made of tiny sensor, even smaller than a fingernail
Choose the Right option
a) Both 1 and 2 Correct
b) Only 1 is Correct
c) Only 2 is Correct
d) Neither 1 not 2 is Correct
Ans a
27) According to the draft Sports Policy of this State Govt released on Jan 11,2012, a Special life-time achievement award in memory of G.V.Raja, the Founder-President of the State Sports Council is to be instituted.Which State is being referred to ?
a) karnataka
b) kerala
c) Tamil Nadu
d) Andhra Pradesh
Ans b
28) Which team defeated Uttarakhand in the Men’s category to win the National title for the fourth time, in the 60th Senior national Volleyball Championship at Raipur on Jan 11, 2012 ?
a) Kerala
b) Andhra Pradesh
c) West Bengal
d) Tamil Nadu
Ans a
29) Which team extended their hegemony by defeating Kerala 25-12, 25-14, 25-16 in a one sided final in the women category at the 60th Senior National Volley-ball Championship ?
a) Punjab
b) Services
c) Railways
d) Delhi
Ans c
30) This Footballer was awarded the 2011 FIFA Ballon d’Oran January 9, 2012 in Zurich. He Won the award for the third Consecutive year for the world’s outstanding footballer.Identify the Footballer ?
a) Cristiano Ronaldo
b) Xavi
c) Sergio Ramos
d) Lionel Messi
Ans d
31) State-run Northern Coalfields(NCL) agreed to surrender land required to mine two blocks attached to the Sasan ultra mega power plant to which of the following Companies giving the Company the benefit over Rs 6000 crore over the life of the Venture ?
1) Reliance Power
2) Adani Power
3) Birla Power Solutions
4) DLF Power
Ans a
32) Which car took home the Crown of Indian car of the Year 2012 in Jan 2012
1) Toyota Etios liva
2) Maruti Suzuki Swift
3) Hyundai Verna
4) Hyundai Eon
Ans b
33) As per the Wholesale Price Index, Published by the govt on Jan 16,2012.Reduced food Prices Caused the inflation to dip to a year low at what percent in December 2011 ?
a) 7.47%
b) 7.65%
c) 6.33%
d) 5.41%
Ans c
34) Maldives Authorities allowed male international airport development and insurance charges from passengers,nearly a month after a local court barred the Bangalore-based company from doing so.Name the operator?
a) GMR Infrastructure
b) International Air Transport
c) Fraport AG
d) DIAL
Ans a
35) Which French Construction major entered the Indian market by buying out 100 percent stake in NAPC, a Chennai-based construction Company?
a) Sinopec Engineering
b) Uhde
c) Vinci
d) Snamprogetti
Ans c
36) India Signed MOU (Memorandum of Understanding ) on Tourism with ASEAN on January12,2012.The agreement took place in-
a) Manado
b) Jakarta
c) Malaysia
d) Manila
Ans a
37) Pravasi Bhartiya Divas-2012 was held in Jaipur.Jaipur is the Capital of which one of the following states?
a) Rajasthan
b) Bihar
c) UP
d) Madhya Pradesh
Ans a
38) India and Japan on Jan 12,2012 agreed to enhance their cooperation in the …………….. Sector.
a) Infrastructure
b) Tourism
c) Road and Transport
d) Coal and Mining
Ans a
39) He was Conferred the first S.K Singh Award for excellence in the Indian Foreign services in Jan 6,2012. Identify the diplomat
a) Ranjan Mathai
b) Shivshankar Menon
c) D.Bala venkatesh Verma
d) K.Raghunath
Ans c
40) Name the auto making company which launched three new variants of the Eon-D-Lite Plus,Era Plus and Magna Plus in the Indian market on jan 2012 ?
a) Tata Motors
b) Hyundai Motors India
c) Volkswagen
d) Maruti Suzuki
Ans b
41) Who was presented the Mahatma Gandhi International Awards for Peace and Reconciliation on Jan 4,2012 the fourth day of the tenth day Kalachakra initiations ?
a) Tibetan Spiritual leader, Dalai Lama
b) South African leader Nelson Mandela
c) Tanzania’s Julius Nyerere
d) Burmese Pro-democracy leader Aung san suu kyi
Ans a
42) European Union agreed in Principle to ban import of Iranian Crude oil.Consider the following statement:
1) The European Union(EU) is one of Iran’s biggest markets for oil.
2) The EU is a Political and economical union of 27 member states
Choose the Right option
a) Both 1 and 2 are correct
b) Only 1 is Correct
c) Only 2 is Correct
d) Neither 1 nor 2 is correct
Ans a
43) The Israel-Palestine talks, in the first week of Jan 2012 were held in Amman.Amman is the Capital of
a) Jordan
b) Syria
c) Iraq
d) Iran
Ans a
44) Maldives on Jan 4,2012 lifted ban on Spas in the upmarket tourist destination .Consider the following statement:
1) The Tourism industry is an important foreign exchange earner in the Maldives.
2) Maldives in 2011 received more than 850000 tourist
Choose the Right Option
a) Both 1 and 2 are correct
b) Only 1 is Correct
c) Only 2 is Correct
d) Neither 1 nor 2 is correct
Ans a
45) India and which country on March 1,2012,decided to open a new chapter in bilateral cooperation by agreeing to undertake joint operations against pirates and sharing technological know how on seabed research?
1) China
2) Japan
3) Russia
4) New Zealand
Ans 1
46) A meeting at the prime minister office on Feb 29,2012, decided to increase the total expenditure on health to what percent of the GDP from the current 1.4 percent by the end of the coming 12th plan period?
1) 2.0 Percent
2) 2.5 Percent
3) 3.0 Percent
4) 4.0 Percent
Ans 2
47) India and which country recently announced to have resolved their longstanding issues of payments for export shipment?
1) Iran
2) Syria
3) Lebanon
4) Pakistan
Ans 1
48) The indigenously development advanced light-weight torpedo and the Akash missile system was on March 3,2012,handed over to the Navy and the Indian Air force respectively at a function in
1) Visakhapatnam
2) Hyderabad
3) Pune
4) Kolkata
Ans 2
49) The golden Jubilee celebrations of Afro-Asian Rural development organization were held in New Delhi in March 2012.The AARDO president hails from
1) India
2) Egypt
3) Morocco
4) South Africa
Ans 2
50) The National Association of Street vendors of India( NASVI ) and Nidan,an organization that supports unorganized workers,were on March 29,2012 honored with the skoll Award for social entrepreneurship by the skoll foundation in
1) Toronto
2) oxford
3) Paris
4) Frankfurt
Ans 2
51) Union minister for Rural development, Drinking Water and sanitation Jairam Ramesh in March 2012 announced a national award for sanitation and water in the name of Maharashtrian saint sant
1) Romesh Hatangadi
2) Gadge Baba
3) Suresh Bhagwan
4) Shiv sagar Baba
Ans 2
52) Who among the following, on march 11,2012,said he will be “Very Sad” if India boycotts the London Olympics following the row over sponsorship of the event by Dow Chemicals, linked to the Bhopal gas tragedy?
1) Barack Obama
2) David Cameron
3) Manmohan singh
4) Hillary Clinton
Ans 2
53) The high level safety review committee recently submitted its report to the Ministry of railways with a Number of recommendations,who is the chairman of this committee ?
1) C.Rangarajan
2) Lalu Yadav
3) Anil Kakodkar
4) Harish Rawat
Ans 3
54) In an important development on March 12,2012, the supreme court issued notices to nsix ministers and eight Indian Administrative services officers from
1) Andhar Pradesh
2) Karnataka
3) Kerala
4) Tamil Nadu
Ans 1
55) Which of the following was pointed by the union Finanace minister Pranab Mukherjee in March 2012 as one of the major challenges facing public sector banks(PSB) in emerging as potential global tenders?
1) Human Capital deficit
2) Human Capital deficit
3) Innovation deficit
4) Technology deficit
Ans 1
56) The Centre told the Supreme Court in March 2012 that it was Probing into the allegations that the former Chief Justice of India and his relatives amassed assets disproportionate to their Known sources of income.Who is the chief Justice in reference here?
1) K.G.Balakrishna
2) S.H.Kapadia
3) Altamas Kabir
4) Dalveer Bhandari
Ans 1
57) The Functioning of both houses of Parliament was disrupted on March 13,2012,When members demanded that India support the resolution to be moved by—— against sri lanka at the U.N Human Rights Council.
1) U.S.A
2) France
3) Norway
4) All of the above
Ans 4
58) Noted critic Namvar Singh in March 2012 presented the Jnanpith Award to eminent hindi author Amar Kant at a Special ceremony in
1) New Delhi
2) Lucknow
3) Allahabad
4) Patna
Ans 3
59) Increasing the fare for the first time in eight years, the railway budget for 2012-13, presented before the parliament on March 14,2012,envisages how many new trains?
1) 90
2) 113
3) 145
4) 166
Ans 2
60) Okram Ibobi Singh was sworn as chief minister for the third Consecutive term of which state in March 2012?
1) Arunachal Pradesh
2) Nagaland
3) Manipur
4) Tripura
Ans 3
61) Governor Shivraj V.Patil in March 2012 administered the oath of office and secrecy to Parkash Singh Badal,Who took over as the chief minister of Punjab for a record- time
1) Fifth
2) Third
3) Fourth
4) Seventh
Ans 1
62) The finance ministry, on March 15,201, gave it’s nod for the labour and employment ministry to fix the rate of interest payable to EEPF sub-subscribers at which percentage for2011-12?
1) 8.25%
2) 8.75%
3) 9.25%
4) 9.50%
Ans 1
63) The Cabinet of which state in march 2012 decided to give a grant of rS. 30,000 to high school pass Muslims girls for perusing their education and marriage?
1) Uttar Pradesh
2) West Bengal
3) Andhra pradesh
4) Delhi
Ans 1
64) Which of the following Chief ministers of India figures on the cover of the Time magazine in March 2012 which prasied him in an article for the development of the State?
1) Mamta Banarjee
2) Nitish Kumar
3) Ashok Gehlot
4) Narendra Modi.
Ans 4
65)The owner of an electronics shop charges his customer 22% more than the the cost price. If a customer paid Rs. 10,980 for a DVD Player, then what was the cost price of the DVD Player?(1) Rs. 8,000
(2) Rs. 8,800
(3) Rs. 9,500
(4) Rs. 9,200
(5) None of these (Ans)
66)Ms Suchi deposits an amount of Rs. 24,000 to obtain a simple interest at the rate of 14 p.c.p.a. for 8 years. What total amount will Ms Suchi get at the end of 8 years?(1) Rs. 52,080
(2) Rs. 28,000
(3) Rs. 50,880 (Ans)
(4) Rs. 26,880
(5) None of these
Explanation : Total Amount= Rs. 24000 + 24000 x 14 x 8/100 = Rs. 50880
67)A canteen requires 112 kgs of wheat for a week. How many kgs of wheat will it require for 69 days?(1) 1,204 kgs
(2) 1,401 kgs
(3) 1,104 kgs (Ans)(4) 1,014 kgs
(5) None of these
Explanation : 112/7 x 69 = 1104 kg= Reqd. quantity of wheat
68)The cost of 4 Cell-phones and 7 Digital cameras is Rs 1,25,627. What is the cost of 8 Cell-phones and 14 Digital cameras?(1) Rs. 2,51,254 (Ans)
(2) Rs. 2,52,627
(3) Rs. 2,25,524
(4) Cannot be determined
(5) None of these
Explanation : 4x + 7y = 125627] x 2? 8x + 14y = 251254
69)Each question has an underlined word followed by four answer choices. You will choose the word that is a necessary part of the underlined word.
17.guitar
A. band
B. teacher
C. songs
D. strings
70) Find the word that names a necessary part of the underlined word.
18. facsimile
A. picture
B. image
C. mimeograph
D. copier
Placement Paper
ONGC chemical engineering questions with answers,ONGC previously asked questions for practice,ONGC memory based engineering questions with answers
Chemical Engineering questions with answers
1Maximum work that could be secured by expanding the gas over a given pressure range is the __________ work.
A. isothermal
B. adiabatic
C. isentropic
D. none of these
Answer: Option A
2. Internal energy change of a system over one complete cycle in a cyclic process is
A. zero
B. +ve
C. -ve
D. dependent on the path
Answer: Option A
3. Heating of water under atmospheric pressure is an __________ process.
A. isochoric
B. isobaric
C. adiabatic
D. isothermal
Answer: Option B
4 Heating of water under atmospheric pressure is an __________ process.
A. isochoric
B. isobaric
C. adiabatic
D. isothermal
Answer: Option B
5 Van Laar equation deals with the activity co-efficients in
A. binary solutions
B. ternary solutions
C. azeotropic mixture only
D. none of these
Answer: Option A
6 Cement Kiln is a
A. rotary Kiln
B. tunnel Kiln
C. natural draft furnace
D. batch furnace
Answer: Option A
7 In a furnace employing forced draught as compared to induced draught,
A. air is sucked in, so air leaks are more and hence the furnace efficiency is reduced.
B. the fan operates hot and hence blades are liable to corrosion and erosion.
C. positive pressure exists in the furnace.
D. none of these
Answer: Option C
8 Regenerators are installed in
A. coke ovens
B. open hearth furnace
C. both (a) & (b)
D. neither (a) nor (b)
Answer: Option C
9 _________ atmosphere is maintained inside an iron blast furnace.
A. Oxidising
B. Reducing
C. Inert
D. Decarburising
Answer: Option B
10 Higher efficiency in the combustion of solid fuel can not be achieved by
A. proper fuel preparation.
B. keeping the flue gas exhaust temperature very high.
C. adopting efficient-fuel firing technique & equipment.
D. supplying correct quantity of combustion air.
Answer: Option B
Descrptive questions with answers
1. What is turndown ratio ?
‘Turndown ratio’ is a flow measurement term that indicates the range a specific flow meter, or meter type, is able to measure…to measure with acceptable accuracy. It is also known as rangeability. It is important when choosing a flow meter technology for a specific application. If a gas flow to be measured is expected to vary between 100,000 m³ per day and 1,000,000 m³ per day, the specific application has a turndown ratio of at 10:1. Therefore the meter requires a turndown ratio of at least 10:1. For example: if the meter had an advertised maximum flow of 2,000,000 m³ per day then the required turndown ratio would be 20:1.
The turndown ratio of each type of meter is limited by theoretical considerations and by practical considerations. For example, orifice meters create a pressure drop in the measured fluid proportional to the square of the velocity. Therefore the range of differential pressure can become too large and compromise accuracy. It can also create process problems such as hydrate formation, and in the case of measuring the discharge of a compressor, there is a limit to how much pressure loss is acceptable.
Turndown ratio is one of a number of considerations in choosing a meter type for an application. Some other considerations are price, maintenance cost, accuracy, the fluid type and the velocity of the flowing fluid.
2. Why Plasticizer is added the paint?
Physical and Chemical Examination of Paints, Varnishes, Lacquers, and … Test by adding plasticizer to the lacquer solution in an amount equal to the base resin
3. What type of glass is used for the manufacture of Electric bulb?
An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light which produces light with a filament wire heated to a high temperature by an electric current passing through it, until it glows (see Incandescence). The hot filament is protected from oxidation with a glass bulb that is filled with inert gas (or evacuated). In a halogen lamp, filament evaporation is prevented by a chemical process that redeposits metal vapor onto the filament, extending its life. The light bulb is supplied with electrical current by feed-through terminals or wires embedded in the glass. Most bulbs are used in a socket which provides mechanical support and electrical connections.
4. Hydrogenation is carried out in which type of reactor?
Chemical … Hydrogenation – to treat with hydrogen – is a chemical reaction between … temperature and/or pressure; 7.3 Flow hydrogenation; 7.4 Industrial reactors … The reduction reaction is carried out at different temperatures and pressures depending upon the substrate and the activity of the catalyst
5. If O2/ Fuel ratio is increased(or, decreased) how adiabatic flame temperature will vary ?
premixed fuel-air mixture will only burn as long as the fuel concentration is between the … the flammable range will widen when the initial temperature is increasing. Changes in initial pressure will for hydrocarbons in air not change the LFL ….
6. Heat loss is maximum when critical radius is
Heat is lost from the pipe to the surrounding medium at temperature , with a convection heat transfer … The value of r2 at which heat transfer rate reaches maximum is determined
7. Importance of Biot No.
A number of important areas were identified: heat transfer … and Biot numbers on the accuracy of the numerical approximation of the diffusion equation for heat …
8. Importance of Dirt Factor…
diRtFactor–Late Models by Speed Sports Software (formerly DWR … If you are missing that “factor” in your life, then you need diRtFactor
9. Why Heavy water is used as moderator in the nuclear reactor ?
Moderator is required in a thermal reactor to slow down the neutrons produced in the fission reaction to .025 ev so that the chain reaction can be
10. Why D2O is used in nuclear reactor instead of ordinary water?
In comparison, in ordinary water, there are only about 156 deuterium atoms per million hydrogen atoms). …. the biological effects of deuterium per se, but instead on deuterium’s ability to …. Heavy water is used in certain types of nuclear reactors where it acts as a …. D2O is more toxic to malignant than normal animal cells .
11. Ordinary water is not preferred in nuclear reactor because
With the discovery of nuclear fission in late 1938, and the need for a neutron … Partly because of Nazi Germany’s over-reliance on heavy water, it did not … Most modern reactors use enriched uranium and normal “light water” (H2O) moderator. ….. large amounts of power, so the chemical methods are generally preferred.
12. Reverse Osmosis is also called
(A) Dialysis
(B) Ultrafiltration
(C) Electrodilysis
(D) Diffusion
Schematics of a reverse osmosis system (desalination) using a pressure exchanger. ….. Prefiltration antiscalants: Scale inhibitors (also known as antiscalants)
13. The specific surface of spherical particle is defined by….
14. The porosity of a compressible cake is
(A) Maximum at the filter medium
(B) Maximum at the upstream face
(C) Same throughout the thickness of cake
(D) Maximum at the filter medium & Minimum at the upstream face.
For a spherical particle of diameter D p, F s =1; for a non-spherical particle, the … The equivalent diameter is sometimes defined as the diameter of a sphere of … in each fraction can be calculated and added to give the specific surface
15. Fermentation of alcohol from molasses is followed by which process..
Various factors namely: process design, molasses quality, yeast strain … interest in ethanol fermentation has been generated over the last two decades … industry and further addresses the steps followed in trouble shooting.
16. Why Dimensional Analysis is done?
In physics and all science, dimensional analysis is a tool to find or check …. the same is done to the dimensional symbols attached to those quantities
17. Dynamic similarity is
(A) The similarity of shapes
(B) The similarity of streamline pattern
(C) The similarity of forces influencing the fluid motion.
(D) The similarity of discharge.
In physics and all science, dimensional analysis is a tool to find or check …. the same is done to the dimensional symbols attached to those quantities
18. What is control Valve..?
Control valves are valves used to control conditions such as flow, pressure, temperature, and liquid level by fully or partially opening
19. Agitated film evaporators are generally used for….
Thin film or wiped film evaporators are used to separate a mixture of liquids having different … Generally the vapour outlet is provided on the top side of the shell.
20. In a multiple effect evaporator with forward feed….
There are two feed operations – backward feed and forward feed operations. A brief explanation of these operations: Multi Effect Evaporators.
21. In a multiple effect evaporator with backward feed….
There are two feed operations – backward feed and forward feed operations. A brief explanation of these operations: Multi Effect Evaporators.
22. Cost of piping in a fluid processing unit(e.g., distillation) of a chemical process plant is about………….. % of the fixed capital investment?
23. Purchased cost of equipment for a chemical process plant ranges from………….. % of the fixed capital investment?
24. Which of the following methods of depreciation calculation results in minimum book value.
25. In finanacial accounting of a chemical plant, which of the following relationship is valid?
26. Which of the following is not a component of the working capital for a chemical process plant?
(A) Product inventory
(B) In-process inventory
(C) Minimum cash reserve
(D) Storage facilities.
27. Effectiveness factor of a catalyst is given by
28. Which of the following substances is most commonly used for cloud seeding (Artificial Rains)?
(A) Potassium chloride
(B) Silver Iodide
(C) Zinc sulphate
(D) Magnesium hydroxide
29. Why the melting and boiling point of alkali metals are high?
30. Which alkali metal will have large ionic radii in water?
(A) Na
(B) K
(C) Cs
(D) H
31. Which alkali halide have large electro negativity?
32. When alkali metals are exposed to air.
33. How Chilton analogy is related to the friction factor?
34. Why Antioxidants are added to petrol
35. Ammonia synthesis from Natural Gas is done by which process
36. Poison for platinum catalyst is..
(A) Sulphur
(B) Arsenic
(C) Phosphorous
(D) Coke
37. Match the following:
(A) Hydrogenation 1. Iron
(B) Ammonia synthesis 2. Platinum
3. Zeolite
4. Nickel
38. Match the following:
(A) Catalytic Reforming 1. High speed Diesel
(B) Smoke Point 2. Kerosene
3. Gasoline
4. Aromatics
39. Match the following:
(A) Xtra mile 1. Indian Oil
(B) Power 2. BP
(C) Speed 3. HP
40. The Bode Stability criterion is applicable when:
(A) Gain and Phase curves decreases continuously with frequency.
(B)Gain curve increases and Phase curves decreases with frequency.
(C)Gain and Phase curves both increses with frequency.
(D)Gain curve decreases and Phase curves increases with frequency.
Placement Paper
ONGC GT (Graduate Trainees )Test is schedules on 4th November,2012 (Sunday)ONGC is looking for promising, energetic and young Geo-scientists, Engineers, MBAs, and CAs/ ICWA?s with bright academic record to join the organization as Class-I executive (E-1) in the following disciplines- Geology, Geophysics, Reservoir, Chemistry, Programming, Production, Drilling, Cementing, Mechanical, Electrical, E&T, Instrumentation, Civil, Transport, Finance, HR, Materials Management, Medical & Security.ONGC questions for practice and model question papers.
ONGC :Graduate Trainees selection Process
ONGC GT (Graduate Trainess) Time Limit 03 Hours
ONGC GT (Graduate Trainess) ELECTRICAL ENGINEERING-208-2009 questions
1 A single phase transformer is connected to a supply of voltage V and frequency f and is supplying a load, connected across its secondary winding. If the supply voltage is reduced from V to V/2, the flux established in the core will
decrease by nearly 50%
increase by nearly 50%
remain unchanged
be affected by amount of load and not by the applied voltage
2 Under magnetic saturation of the core of a transformer, the reactance parameters of its equivalent circuit are affected such that
X1 and X2 increase while Xm does not change
X1 and X2 do not change while Xm decreases
X1 and X2 do not change while Xm increases
X1 and X2 decreases while Xm does not change
3 A single phase 2000/200 V, 10 kVA, two winding transformer is reconnected as a step-up autotransformer with 2000 V winding as primary. The kVA rating of the autotransformer shall be
10 kVA
11 kVA
110 kVA
220 kVA
4 The power factor at which power is drawn by a transformer is
very low under O.C. test but high under S.C. test
high under O.C. test but low under S.C. test
low both under O.C. and S.C. tests
high both under O.C. and S.C. tests
5 The O.C.C. of a shunt d.c. generator is represented by E = 12+66I. If the field resistance is 70 ohms, the no-load voltage of the generator will be
144 V
210 V
220 V
288 V
6 In d.c. shunt motors, the developed torque is proportional to
induced e.m.f.
armature current
output power
line current
7 The speed of a separately excited d.c. motor can be controlled below base speed by (a) armature resistance control and (b) supply voltage control. What happens to the slope of modified speed-torque characteristics under the two methods?
It changes in both types of control
It remains unchanged in both types of control
It remains unchanged in armature resistance control while changes in supply voltage control
It remains unchanged in supply voltage control while changes in armature resistance control
8 The polarity of interpoles used in d.c. machines is
same as the main pole ahead in generators while opposite of the main pole ahead in motors
same as the main pole ahead ion motors while opposite of the main pole ahead in generators
same as the main pole ahead in both motors and generators
opposite of the main pole ahead in both motors and generators
9 In synchronous generators, examine the following statements about voltage regulation:
Synchronous impedance method gives pessimistic results
MMF method gives optimistic results
In unsaturated machine both methods (synchronous impedance and MMF) give same result
Which of the statements are correct?
1, 2 and 3
Only 1 and 2
Only 3
Only 2 and 3
10 Under symmetrical short circuit of a synchronous generator, the armature reaction is
magnetizing
demagnetizing
cross-magnetising
mainly magnetising
11 In synchronous generators, the fifth harmonic in induced emf can be eliminated by using coils show chorded by an angle
9o
18o
27 o
36o
12 In induction motor operation, a slip greater than 1 refers to
regenerative braking
motoring in reverse direction
plugging
dynamic braking
13 As the applied voltage to an induction motor, operating under no-load, is reduced to half
its speed reduced and stator current increases
its speed reduced and stator current also reduces
its speed reduces but there is not change in stator current
there is no change in speed but stator current reduces
14 A 3-phase induction motor is delivering a load of 10 kW at a lagging p.f. of 0.5. If a 3-phase capacitor bank of 7.3 kVAR is connected at its input, the resulting kVA drawn from supply shall be (approximately)
26.5
24.5
20.0
14.0
15 An electric motor developing a starting torque of 10 Nm starts with a load of 6 Nm at its shaft. If the acceleration at start is 2 rad/sec2 , the moment of inertia of the system must be
2 kg-m2
2 N-m2
0.5 kg-m2
0.5 N-m2
16 A synchronous motor works as a synchronous condenser if
underexcited
overexcited
excited with 100% excitation
unexcited
17 In relation to damper bar winding in a synchronous motor, examine the following statements:
Damper bars are provided in slots on poles
Damper bars improve excitation
Damper bars help the motor self start
Damper bars minimize hunting.
Which of the statements are correct?
1, 2, 3
2, 3
1, 4
1, 3, 4
18 In large power ratings, synchronous motor is considered superior to induction motor, since
it is less expensive
its efficiency is better
it can be operated at better power factor
its speed regulation is superior.
19 An induction motor drive is designed for two speed operation. For this purpose, the motor is provided with two windings on its stator corresponding to 4 poles and 8 poles. While the motor was running on 4 pole winding, a changeover to 8 pole winding is made. The motor will
experience dynamic braking
experience regenerative braking
experience no braking but will slow down due to its inertia
draw dangerously high current
20 A d.c. shunt motor drive of 100 h.p. is run (a) at half the rated speed by armature voltage control and (b) at 1.5 times the rated speed by field control. Its power rating in the two cases shall be modified as
100 h.p. in both cases
50 h.p. in case (a) and 150 h.p. in case (b)
50 h.p. in case (a) and 100 h.p. in case (b)
100 h.p. in case (a) and 150 h.p. in case (b)
21 A single phase full controlled rectifier can work as inverter, if the firing angle is between
0o and 90o
60o and 90o
90o and 180o
0o and 60o
22 When d.c. voltage is converted to a.c. by an inverter, PWM technique is used to
control only the output voltage from within the inverter
control both the output voltage and frequency from within the inverter
control the output current
reduce losses in the inverter
23 A thyristor which is in ON state is to be switched OFF. For this purpose a reverse bias is applied across it. Examine the following statements regarding flow of current from anode to cathode (forward current):
Forward current can continue to flow if the circuit is purely resistive
Forward current can continue to flow if the circuit is dominantly inductive
Forward current can continue to flow if the circuit is dominantly capacitive
Forward current will immediately stop flowing.
24 Which of the above statements are correct?
Only 4
Only 1
Only 2 and 3
Only 2
25 In a 3-phase full controlled thyristor bridge rectifier operating under continuous conduction mode, each thyristor conducts for
180o and two thyristors conduct at a time
120o and three thyristors conduct at a time
180o and three thyristors conduct at a time
120o and two thyristors conduct at a time
26 A single phase fully controlled rectifier is feeding a d.c. motor. At a = 0o, the armature voltage is 200 V and motor speed is 1000 rpm. Neglecting armature resistance and considering continuous conduction, the armature voltage and speed at a = 60o will be
100 V and 500 rpm
100 V and 1000 rpm
200 V and 500 rpm
100 V and speed will depend upon load
27 The grading capacitors are provided across the series connected interrupters in EHV circuit breakers for
reducing short circuit current
improving power factor
equalizing distribution of recovery voltage across the interrupters
preventing inductive current chopping.
28 The minimum cost operating condition for a thermal plant is that
the larger units should generate more power as compared to smaller units
the smaller units should generate more power as compared to larger units
the incremental cost rate of the units be proportional to their rating
the incremental cost rate of all the units be equal
29 The effect of earth on a three-phase transmission line is to
increase its capacitance and decrease inductance
decrease its capacitance and increase inductance
increase its capacitance without affecting inductance
increase its inductance without affecting capacitance.
30 In case of a transmission line if the voltage regulation is negative, then the load power factor is
zero
lagging
unity
leading
ONGC whole Test paper,for practice, ONGC latest general awareness, aptitude questions, Technical questions, ONGC model questions for practice
ONGC verbal ability questions with answers and solved technical questions with answers,ongc free solved sample placement papers
1. The nearest meaning of the word COARSE is _____.
a. Impolite
b. Rough – ans
c. Polish
d. Improper
2. The insulation resistance of a cable wire is 300 mega ohm per km. Its value for the length of 500 metre is ______.
a. 600 mega ohm
b. 300 mega ohm
c. 75 mega ohm
d. 150 mega ohm – ans
3. In a certain code language RUSH is written as 66. How will GIRL be written in the same code language?
a. 75
b. 64
c. 47
d. 46 – ans
4. In a row of 25 children, Nayan is fourteenth from the right end. In the row, Arun is third to the left of Nayan. What is the place of Arun from the left in the row ?
a. Tenth
b. Seventh
c. Eight
d. Ninth – ans
5. Choose the word that is most nearly opposite in meaning to the word:-
Aggressive
a. Assertive
b. Proud
c.
Whole-Testpaper
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ONGC G.K. questions were
1. Bear lake is in which country?
2. River cutting tropic of Capricorn twice.
3. Author of NEEL DARPAN
4. Chairman of Congress when Surat split 1907 held.
5. Min age defined for the judge of Supreme Court.
6. Most sweet naturally occuring sugar.
7. Which vitamin deficiency cause pallegra?
8. Fundamental rights were first raised in the which summit of INC
9. President submits his resignation to whom?
10. Tipaimukh DAM is in which state?
11. Krishna River originates from which part
12. Tadri Ultra Mega Power Project is in which state
13.Name the State with highest decay in population growth rate?
14. Sex ratio of India as per latest census
15. MANSABDARI system was introduced by which Mughal emperor?
16. Which championship was won by Grandmaster Parimarjan Negi?
17. Which two cities connected by NH-15 join?
18. National Solar Mission is to ensure 20000 MW power production by which year?
19. Which is the Highest Peak of SATPURA RANGE?
20. Moplah Rebellion occurred in 1921 in which part of the country?[options were a)coromandal coast b)malabar coast c)Punjab]
21. Who is the Political Guru of Mahatma Gandhi?
22. 2010 FIFA world cup will held in which country?
23. Who is the Chairman of the Scientific Advisory Council to the Indian Prime Minister?
24. In Assembly elections state in which a single party has won all seats?
25. First Pvt. Company being provided CISF security?
26. Indian Space Application Center is located in which city?
27 .When sun is nearest to earth it is called?
28. Which two countries did KONKAN naval task?
29. Who started ?All India Untouchibilty Abolishment Program??
30. In which city first Buddhist council held?
31. Who got Rajiv Gandhi Sadbhavna award in 2010?
32. Which among of them are types of RBC?s?
33. In which country 16-COP submit will going to be held?
34. In which city National Environmental Engineering Research institute was first opened?
35. Place emerges as new mobile hub in India?
36. Name the instrument use to measure blood pressure?
37. Arihant was the first submarine built by India. What is its capacity?
38. Teacher?s day is celebrated in the honour of which person?
39. Child labour prevention act is in which article?
40. Who is the new head of International Institute of Educational planning?
Descriptive in G. K.
1. Explain ?Unity in diversity? in India
2. Impact of globalization on rural economy.
Technical
1. What is the expression of Thiele modulus?
2. Reynold?s no. Is defined as ratio of (ans. Intertial force/viscous force)
3. Prandtl no. Is defined as the ratio of (momentum diffusivity /thermal diffusivity)
4. Aeration and agitation is used in which type of culture?
5. Penicillin is the product obtained at which stage?
6. Which among the following type autocatalyst reaction occurs the most? [a)esterfication b)saponification c)biological d)oxidation]
7. Which of the following does not effect the cake filteration? [a)fluid b)fluid medium c)pressure drop d)temperature]
8. What is the range of ultrafilteration product? [a)1-50 microm b)50-100 c)100-150 d)150-200]
9. Fluid mill is used for which of the following filteration process?
10. In a reactor 87% carbon passes, 7% unoxidised hydrogen passes. What will be the oxygen required per kg of carbon dioxide produced if 40% extra air is passed?
11. What is the condition of equilibrium? [a)entropy minimum b)gibb?s energy minimum c)temperature minimum d) pressure minimum]
12. Which condition is unfavourable for spontaneity of reaction? [a) G<0 b)G=0 c)G>0 d)G=1?
13. The terminal velocity is directly proportional to?(ans. Sq. Of diameter)
14. Ore of potassium?(ans. sylvinite)
15. Phosphorus is added in medium ?[a)increase buffer capacity b)decrease buffer capacity c)increase resistance against contamination d) increase production of bacteria)
16. What will be the volume of 15 kg chlorine at 293K, .9 bar pressure?
17. Kraft process is used for the production of which product?(ans. Paper)
18. What are the major raw material for silicone production?(ans. Sand and carbon)
19. What is the purity of metallurgical obtained silicone? (Ans. 98%)
20. Dittus-boelter expression is used for ?(ans. turbulent flow)
21. Effectivness factor can be improved by?(ans. Increase size of catalyst particle and decreasing diffusivity of catalyst)
22. What is the co-ordination no. And packing efficiency of diamond?
23. Rayleigh equation can be obtained by using?( ans. Nusslet no. and grashoff no. )
24. Which force act in radial direction in cyclone seperator?( ans. Centrifugal force)
25. What is the expression to calculate height of the tower?( ans. NTU*HTU)
26. NTU method is used to calculate? (ans. No of stages involved)
27. Why LMTD is used? (ans. Because temperature change is not constant in Heat exchanger)
28. Designing of heat exchanger is based on? [ans. a)type of heat exchanger b)area of heat exchanger c)volume of heat exchanger d) shape of heat exchanger]
29. Phase rule is given by? [a)gibb?s b)joule c) vant hoff d) Thomson]
30. What is the degree of freedom at triple point of water? (ans. Zero)
31. Activation energy is maximum for? [a)endothermic reactions b)exothermic reactions c)homogeneous d)heterogeneous]
32. What is the shape of dilatent fluid toward Newtonian fluid? (ans. Convex toward it)
33. What is the shape of q-line at saturated vapour conditions? (ans. Horizontal)
34. With increase in temperature the viscosity of the liquid? (ans. Decreases)
35. Among which two quantities the curve will plot to see the binary system at constant pressure and volume?( ans. tem. and concentration)
36. What is the effect of change in set point with change in load point?
37. What is the heat of reaction? (ans. Heat of product-heat of reactant at 373)
38. Drying phenomena will occur? [a)above b.pt b)below boiling pt. c)equal to b.pt d)at G=0)
39. In which of the following phenomena evaporation is a necessary phenomenon? [a)drying b)evaporation c)leeching d)distillation]
40. In lyophilisation the method of storage is..?[a)drying b)sublimation c)evaporation ]
There were two ques. Which were numerical…..
I must say if u want clear ONGC….then stick to the concepts…and u should b very-very good in G.K.
Whole-Testpaper
ONGC Placement Paper For Mechanical
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SECTION 1-MECHANICAL
1 During the execution of a CNC part program block NO20 GO2 X45.0 Y25.0 R5.0 the type of tool motion will be
A) circular Interpolation ? clockwise
B) circular Interpolation ? counterclockwise
C) linear Interpolation
D) rapid feed
Answer : (A)
2 A component can be produced by any of the four processes I, II, III and IV. Process I has a fixed cost ofRs. 20 and variable cost of Rs. 3 per piece. Process II has a fixed cost Rs. 50 and variable cost of Re. 1 per piece. Process III has a fixed cost of Rs. 40 and variable cost of Rs. 2 per piece. Process IV has a fixed cost of Rs. 10 and variable cost of Rs. 4 per piece. If the company wishes to produce 100 pieces of the component, from economic point of view it should choose
A) Process I
B) Process II
C) Process III
D) Process IV
Answer : (B)
3 In an interchangeable assembly, shafts of size 25.000+0.040mm mate with holes of size 25.000+0.020 mm. The maximum possible clearance in the assembly will be
A) 10 microns
B) 20 microns
C) 30 microns
D) 60 microns
Answer : (D)
4 A company has two factories S1, S2 and two warehouses D1, D2. The supplies from S1 and S2 are 50 and 40 units respectively. Warehouse D1 requires a minimum of 20 units and a maximum of 40 units. Warehouse D2 requires a minimum of 20 units and, over and above, it can take as much as can be supplied. A balanced transportation problem is to be formulated for the above situation. The number of supply points, the number of demand points, and the total supply (or total demand) in the balanced transportation problem respectively are
A) 2, 4, 90
B) 2, 4, 110
C) 3, 4, 90
D) 3, 4, 110
Answer : (C)
5 An incompressible fluid (kinematic viscosity, 7.4 x 10-7 m2/s, specific gravity, 0.88) is held between two parallel plates. If the top plate is moved with a velocity of 0.5 m/s while the bottom one is held stationary, the fluid attains a linear velocity profile in the gap of 0.5 mm between these plates; the shear stress in Pascals on the surface of top plate is
A) 0.651 x 10-3
B) 0.651
C) 6.51
D) 0.651 x 103
Answer : (B)
6 The tool of an NC machine has to move along a circular arc from (5,5) to (10,10) while performing an operation. The centre of the arc is at (10,5). Which one of the following NC tool path commands performs the above mentioned operation?
A) N010 G02 X10 Y10 X5 Y5 R5
B) N010 G03 X10 Y10 X5 Y5 R5
C) N010 G01 X5 Y5 X10 Y10 R5
D) N010 G02 X5 Y5 X10 Y10 R5
Answer : (D)
7 During a Morse test on a 4 cylinder engine, the following measurements of brake power were taken at constant speed.
All cylinders firing 3037 kW
Number 1 cylinder not firing 2102 kW
Number 2 cylinder not firing 2102 kW
Number 3 cylinder not firing 2100 kW
Number 4 cylinder not firing 2098 kW
The mechanical efficiency of the engine is
A) 91.53%
B) 85.07%
C) 81.07%
D) 61.22%
Answer : (C)
8 In terms of theoretical stress concentration factor (Kt) and fatigue stress concentration factor (Kf ), the notch sensitivity ?q? is expressed as
A) (Kf -1) (Kt -1)
B) (Kf -1) (Kt +1)
C) (Kt -1) (Kf -1)
D) (Kf +1) (Kt +1)
Answer : (A)
9 Starting from x0 = 1, one step of Newton-Raphson method in solving the equation x3 + 3x -7 = 0 gives the next value (x1) as
A) x1 = 0.5
B) x1= 1.406
C) x1= 1.5
D) x1 = 2
Answer : (C)
10 The S-N curve for steel becomes asymptotic nearly at
A) 103 cycles
B) 104 cycles
C) 10 6 cycles
D) 10 9 cycles
Answer : (C)
11. In PERT analysis a critical activity has
A) maximum Float
B) zero Float
C) maximum Cost
D) minimum Cost
Answer : (B)
12 Environment friendly refrigerant R134a is used inthe new generation domestic refrigerators. Itschemical formula is
A) CH C1 F2
B) C2 C13 F3
C) C2 C12 F4
D) C2 H2 F4
Answer : (D)
13 A solid cylinder (surface 2) is located at the centreof a hollow sphere (surface 1). The diameter of the sphere is 1m, while the cylinder has a diameter and length of 0.5 m each. The radiation configuration factor F11 is
A) 0.375
B) 0.625
C) 0.75
D) 1
Answer : (C)
14 For a fluid flow through a divergent pipe of length L having inlet and outlet radii of R1 and R2 respectively and a constant flow rate of Q, assuming the velocity to be axial and uniform at any cross-section, the acceleration at the exit is
A) 2Q(R1 – R2) p LR23
B) 2Q2 (R1 – R2) p LR23
C) 2Q2 (R1 – R2) p2LR25
D) 2Q2 (R2 – R1) p2LR25
Answer : (C)
15 An incompressible fluid (kinematic viscosity, 7.4 x 10-7 m2/s, specific gravity, 0.88) is held between two parallel plates. If the top plate is moved with a velocity of 0.5 m/s while the bottom one is held stationary, the fluid attains a linear velocity profile in the gap of 0.5 mm between these plates; the shear stress in Pascals on the surface of top plate is
A) 0.651 x 10-3
B) 0.651
C) 6.51
D) 0.651 x 103
Answer : (B)
16 The tool of an NC machine has to move along a circular arc from (5,5) to (10,10) while performing an operation. The centre of the arc is at (10,5). Which one of the following NC tool path commands performs the above mentioned operation?
A) N010 G02 X10 Y10 X5 Y5 R5
B) N010 G03 X10 Y10 X5 Y5 R5
C) N010 G01 X5 Y5 X10 Y10 R5
D) N010 G02 X5 Y5 X10 Y10 R5
Answer : (D)
17 During a Morse test on a 4 cylinder engine, the following measurements of brake power were taken at constant speed.
All cylinders firing 3037 kW
Number 1 cylinder not firing 2102 kW
Number 2 cylinder not firing 2102 kW
Number 3 cylinder not firing 2100 kW
Number 4 cylinder not firing 2098 kW
The mechanical efficiency of the engine is
A) 91.53%
B) 85.07%
C) 81.07%
D) 61.22%
Answer : (C)
18 In terms of theoretical stress concentration factor(Kt) and fatigue stress concentration factor (Kf ), the notch sensitivity ?q? is expressed as
A) (Kf -1) (Kt -1)
B) (Kf -1) (Kt +1)
C) (Kt -1) (Kf -1)
D) (Kf +1) (Kt +1)
Answer : (A)
19 Starting from x0 = 1, one step of Newton-Raphson method in solving the equation x3 + 3x -7 = 0 gives the next value (x1) as
A) x1 = 0.5
B) x1= 1.406
C) x1= 1.5
D) x1 = 2
Answer : (C)
20 A maintenance service facility has Poisson arrival rates, negative exponential service time and operates on a ?first come first served? queue discipline. Break downs occur on an average of 3 per day with a range of zero to eight. The maintenance crew can service an average of 6 machines per day with a range of zero to seven. The mean waiting time for an item to be serviced would be
A) 16 day
B) 13 day
C) 1 day
D) 3 days
Answer : (A)
21 The S-N curve for steel becomes asymptotic nearly at
A) 103 cycles
B) 104 cycles
C) 106 cycles
D) 109 cycles
Answer : (C)
22 In a rolling process, sheet of 25 mm thickness is rolled to 20 mm thickness. Roll is of diameter 600 mm and it rotates at 100 rpm. The roll strip contact length will be
A) 5 mm
B) 39 mm
C) 78mm
D) 120mm
Answer : (A)
23 Water at 42°C is sprayed into a stream of air at atmospheric pressure, dry bulb temperature of 40°C and a wet bulb temperature of 20°C. The air leaving the spray humidifier is not saturated. Which of the following statements is true?
A) Air gets cooled and humidified
B) Air gets heated and humidified
C) Air gets heated and dehumidified
D) Air gets cooled and dehumidified
Answer : (B)
24 The angle between two unit-magnitude coplanar vectors P(0.866, 0.500,0) and Q(0.259, 0.966,0) will be
A) 0°
B) -30°
C) 45°
D) 60°
Answer : (C)
25 A lot has 10% defective items. Ten items are chosen randomly from this lot. The probability that exactly 2 of the chosen items are defective is
A) 0.0036
B) 0.1937
C) 0.2234
D) 0.3874
Answer : (B)
26 Stokes theorem connects
A) a line integral and a surface integral
B) a surface integral and a volume integral
C) a line integral and a volume integral
D) gradient of a function and its surface integral
Answer : (A)
27 A solar collector receiving solar radiation at the rate of 0.6 k W/m2 transforms it to the internal energy of a fluid at an overall efficiency of 50%. The fluid heated to 350 K is used to run a heat engine which rejects heat at 313 K. If the heat engine is to deliver 2.5 kW power, the minimum area of the solar collector required would be
A) 8.33m2
B) 16.66m2
C) 39.68m2
D) 79.36m2
Answer : (D)
28 When the temperature of a solid metal increases,
A) strength of the metal decreaes but ductility increases
B) both strength and ductility of the metal decrease
C) both strength and ductility of the metal increase
D) strength of the metal increases but ductility decreases
Answer : (A)
29 A company produces two types of toys: P and Q. Production time of Q is twice that of P and the company has a maximum of 2000 time units per day. The supply of raw material is just sufficient to produce 1500 toys (of any type) per day. Toy type Q requires an electric switch which is available @ 600 pieces per day only. The company makes a profit of Rs. 3 and Rs. 5 on type P and Q respectively. For maximization of profits, the daily production quantities of P and Q toys should respectively be
A) 100, 500
B) 500, 1000
C) 800, 600
D) 1000, 1000
Answer : (C)
30 A spherical thermocouple junction of diameter 0.706 mm is to be used for the measurement Aof temperature of a gas stream. The convective heat transfer co-efficient on the bead surface is 400 W/m2K. Thermophysical properties of thermocouple material are k = 20 W/mK, C = 400 J/kg K and r = 8500 kg/m3. If the thermocouple initially tot 30°C is placed in a hot stream of 300°C, the time taken by the bead to reach 298°C, is
A) 2.35 s
B) 4.9 s
C) 14.7 s
D) 29.4 s
Answer : (B)
31 In a spring-mass system, the mass is 0.1 kg and the stiffness of the spring is 1 kN/m. By introducing a damper, the frequency of oscillation is found to be 90% of the original value. What is the damping coefficient of the damper?
A) 1.2 N.s/m
B) 3.4 N.s/m
C) 8.7 N.s/m
D) 12.0 N.s/m
Answer : (C)
32.In a machining operation, doubling the cutting speed reduces the tool life to 1/8 of the original value. The exponent n in Taylor
A) 1/8
B) 1/4
C) 1/3
D) 1/2
Answer : (C)
33.In a rolling process, sheet of 25 mm thickness is rolled to 20 mm thickness. Roll is of diameter 600 mm and it rotates at 100 rpm. The roll strip contact length will be
A) 5 mm
B) 39 mm
C) 78 mm
D) 120 mm
Answer : (A)
34.A soldering operation was work-sampled over two days (16 hours) during which an employee soldered 108 joints. Actual working time was 90% of the total time and the performance rating was estimated to be 120 percent. If the contract provides allowance of 20 percent of the total time available, the standard time for the operation would be
A) 8 min
B) 8.9 min
C) 10 min
D) 12 min
Answer : (D)
35. A welding operation is time-studied during which an operator was pace-rated as 120%. The operator took, on an average, 8 minutes for producing the weld-joint. If a total of 10% allowances are allowed for this operation, the expected standard production rate of the weld-joint (in units per 8 hour day) is
A) 45
B) 50
C) 55
D) 60
Answer : (A)
36. In PERT analysis a critical activity has
A) maximum Float
B) zero Float
C) maximum Cost
D) minimum Cost
Answer : (B)
37.Environment friendly refrigerant R134a is used in the new generation domestic refrigerators. Its chemical formula is
A) CH C1 F2
B) C2 C13 F3
C) C2 C12 F4
D) C2 H2 F4
Answer : (D)
38. The parabolic arc y = x, 1 ? x ? 2 is revolved around the x-axis. The volume of
the solid of revolution is
(A)4?
(B)2?
(C)34?
(D)32?
39. A moist air sample has dry bulb temperature of 30ºC and specific humidity of
11.5g water vapour per kg dry air. Assume molecular weight of air as 28.93. If
the saturation vapour pressure of water at 30ºC is 4.24kPa and the total pressure
is 90kPa, then the relative humidity (in %) of air sample is
(A) 50.5 (B) 38.5 (C) 56.5 (D) 68.5
40. The value of the integral 2dx1 x??? + ? is
(A) ??
(B)2??
(C)2?
(D) ?
41. The modulus of the complex number
? 3+ 4i ?? 1 ? 2i? ? ?is
(A) 5
(B) 5
(C)1
(D)15
42. The function y = 2 ? 3x
(A) is continuous ?x ? R and differentiable ?x ? R
(B) is continuous ?x ? R and differentiable ?x ? R except at x=3/2
(C) is continuous ?x ? R and differentiable ?x ? R except at x=2/3
(D) is continuous ?x ? R except at x=3 and differentiable ?x ? R
6. Mobility of a statically indeterminate structure is
(A) ? ?1 (B) 0 (C) 1 (D) ? 2
43. There are two points P and Q on a planar rigid body. The relative velocity
between the two points
(A) should always be along PQ
(B) Can be oriented along any direction
(C) should always be perpendicular to PQ
(D) should be along QP when the body undergoes pure translation
44. The state of plane-stress at a point is given by ?x = ?200MPa, ?y = 100MPa and ?xy = 100MPa. The maximum shear stress in MPa is
(A) 111.8
(B) 150.1
(C) 180.3
(D) 223.6
45. Which of the following statements is INCORRECT?
(A) Grashof?s rule states that for a planar crank-rocker four bar mechanism, the
sum of the shortest and longest link lengths cannot be less than the sum of
the remaining two link lengths.
(B) Inversions of a mechanism are created by fixing different links one at a time.
(C) Geneva mechanism is an intermittent motion device
(D) Gruebler?s criterion assumes mobility of a planar mechanism to be one.
46. The natural frequency of a spring-mass system on earth is ?n. The natural frequency of this system on the moon (gmoon = gearth / 6) is
(A) ?n
(B)0.408?n
(C) 0.204?n
(D) 0.167?n
47. Tooth interference in an external involute spur gear pair can be reduced by
(A) decreasing center distance between gear pair
(B) decreasing module
(C) decreasing pressure angle
(D) increasing number of gear teeth
48. For the stability of a floating body, under the influence of gravity alone, which of
the following is TRUE?
(A) Metacentre should be below centre of gravity
(B) Metacentre should be above centre of gravity
(C) Metacentre and centre of gravity must lie on the same horizontal line
(D) Metacentre and centre of gravity must lie on the same vertical line
49. The maximum velocity of a one-dimensional incompressible fully developed viscous flow, between two fixed parallel plates, is 6ms-1. The mean velocity (in ms-1) of the flow is
(A) 2
(B) 3
(C) 4
(D) 5
50. A phenomenon is modeled using n dimensional variables with k primary dimensions. The number of non-dimensional variables is
(A) k
(B) n
(C) n-k
(D) n+k
51. A turbo-charged four-stroke direct injection diesel engine has a displacement volume of 0.0259m3 (25.9litres) . The engine has an output of 950kW at 2200rpm. The mean effective pressure in MPa is closest to
(A) 2
(B) 1
(C) 0.2
(D) 0.1
52. One kilogram of water at room temperature is brought into contact with a high temperature thermal reservoir. The entropy change of the universe is
(A) equal to entropy change of the reservoir
(B) equal to entropy change of water
(C) equal to zero
(D) always positive
53. A hydraulic turbine develops 1000kW power for a head of 40m. If the head is reduced to 20m, the power developed (in kW) is
(A) 77
(B) 354
(C) 500
(D) 707
54. The material property which depends only on the basic crystal structure is
(A) fatigue strength
(B) work hardening
(C) fracture strength
(D) elastic constant
55. In a gating system, the ratio 1:2:4 represents
(A) sprue base area: runner area: ingate area
(B) pouring basin area: ingate area: runner area
(C) sprue base area: ingate area: casting area
(D) runner area: ingate area: casting area
56. A shaft has a dimension, 0.009 35 0.025 ?? ? . The respective values of fundamental deviation
and tolerance are
(A) ?0.025, ± 0.008
(B) ?0.025,0.016
(C) ?0.009, ±0.008
(D) ?0.009,0.016
57. In a CNC program block, N002 G02 G91 X40 Z40?, G02 AND G91 refer to
(A) circular interpolation in counterclockwise direction and incremental dimension
(B) circular interpolation in counterclockwise direction and absolute dimension
(C) circular interpolation in clockwise direction and incremental dimension
(D) circular interpolation in clockwise direction and absolute dimension
58. The demand and forecast for February are 12000 and 10275, respectively. Using
single exponential smoothening method (smoothening coefficient = 0.25),
forecast for the month of March is
(A) 431
(B) 9587
(C) 10706
(D) 11000
59. Little?s law is relationship between
(A) stock level and lead time in an inventory system
(B) waiting time and length of the queue in a queuing system
(C) number of machines and job due dates in a scheduling problem
(D) uncertainty in the activity time and project completion time
60. Vehicle manufacturing assembly line is an example of
(A) product layout
(B) process layout
(C) manual layout
(D) fixed layout
61. Simplex method of solving linear programming problem uses
(A) all the points in the feasible region
(B) only the corner points of the feasible region
ONGC electrical question papers
ONGC previous years electrical Engineering questions with answers
1. In a D.C. generator, if the brushes are given a small amount of forward shift, the effect of armature is
a. Totally demagnetizing
b. Totally magnetizing
c. Partly demagnetizing and partly cross magnetizing
d. Totally cross magnetizing
2. The air gap between stator and armature of an electric motor is kept as small as possible
a. To get a stronger magnetic field
b. to improve the air circulation
c. To reach the higher speed of rotation
d. To make the rotation easier.
3. Two series motors are coupled. One motor runs as generator and other as motor. The friction losses of the two machines will be equal when
a. Both operates at same voltage
b. Both have same back emf
c. Both have same speed
d. both have same excitation
4. Plugging of D.C. motor is normally executed by
a. Reversing the field polarity
b. Reversing the armature polarity
c. Reversing both the armature and field polarity
d. Connecting a resistance across the armature.
5. Transformer oil transformer provides
a. Insulation and cooling
b. B. Cooling and lubrication
c. Lubrication and insulation
d. Insulation, cooling and lubrication
6. Leakage fluxes of transformer may be minimized by
a. Reducing the magnetizing current to the minimum
b. Reducing the reluctance of the iron core to the minimum
c. Reducing the number of primary and secondary turn to the minimum
d. Sectionalizing and interleaving the primary and secondary windings
7. Electric power is transformed upon one coil to other coil in a transformer
a. Electrically
b. Electro Magnetically
c. Magnetically
d. Physically
8. The most suitable and economical connection for small high voltage transformer is-
a. Star- Delta connection
b. Delta- Delta connection
c. Delta- Star connection
d. Star- Star connection
9. An alternator is said to be over excited when it is operating at
a. Unity power factor
b. Leading power factor
c. Lagging power factor
d. Either lagging or leading power factor
10. In an A.C. machine, the armature winding is kept stationary while the field winding is kept rotating for the following rason
a. Armature handles very large currents and high voltages
b. Armature friction involving deep slots to accommodate large coils is easy if armature is kept stationary
c. Ease of cooling the stator than rotor
d. None of the above.
11. In a synchronous motor, the torque angle is the
a. Angle between the rotating stator flux and rotor poles
b. Angle between the magnetizing current and back emf
c. Angle between the supply voltage and back emf
d. None of the above
12. A 3-phase synchronous motor is said to be “floating” when it operates
a. On no load and without loss
b. On constantly varying load
c. On pulsating load
d. On high load and variable supply voltage
13. Speed of synchronous motor depends upon
a. Number of poles
b. Supply frequency
c. Both (a) and (b)
d. Neither (a) nor (b)
14. Imbalance in the shaft of an induction motor occurs due to
a. Slip rings
b. Overheating of winding
c. Non uniform of air gap
d. Rigid consturcion
15. Squirrel cage induction motor has
a. Zero starting torque
b. Very small starting torque
c. Medium starting torque
d. Very high starting torque
16. The principle of operation of a 3-phase induction motor is similar to that of a
a. Synchronous motor
b. Repulsion – start induction motor
c. Transformer with a shorted secondary
d. Capacitor – start, induction – run motor
17. The speed/load characteristics of a universal motor are similar to those
a. D.C. shunt motor
b. D.C. series motor
c. A.C. motor
d. None of the above
18. Single phase A.C. motor generally used for vacuum cleaners is
a. Universal motor
b. Repulsion motor
c. Hysteresis motor
d. Reluctance motor
19. Buchholz relay is used for the protection of
a. Switch yard
b. Transformers
c. Alternators
d. Transmission lines
20. The type of braking used in traction system is
a. Mechanical braking
b. Electro – pneumatic braking
c. Vacuum braking system
d. All the above
21. The function of processing zenger diode in a UJT circuit used for triggering of SCRs is to
a. Expedite the generation of triggering pulses
b. Delay the generation of triggering pulses
c. Provide a constant voltage to UJT to prevent erratic firing
d. Provide a variable voltage to UJT as the source voltage changes
22. The frequency of a ripple in the output voltage of a 3 – phase semi converter depends upon
a. Firing angle and load resistance
b. Firing angle and supply frequency
c. Firing angle and load inductance
d. Only on load circuit parameters
23. The SCR is turned off when the anode currents falls below
a. Forward current rating
b. Break – over voltage
c. Holding current
d. Latching
24. V4 characteristics of emitter of a UJT is
a. Similar to CE with linear and saturation region
b. Similar to FET with a linear and pinch of region
c. Similar to tunnel diode in some respects
d. Linear between the peak point and valley point
25. A transformer works on
a. DC
b. AC
c. AC & DC both
d. Neither AC not DC
26. Which of the following device is used in transformer?
a. Tube light
b. Electric heater
c. Mobile phone
d. Rectifier module
27. Earth electrodes can be in the form of
a. rods or piper
b. stripes
c. plates
d. any of above
28. Carbone or metal brushes are used in
a. DC generators only
b. AC generators only
c. Both AC & DC generation
d. None of above
29. Energy is lost due to Joule’s heating effects in winding of transformer. This is called
a. Copper loss
b. Eddy current loss
c. Flux loss
d. None
30. In refrigeration cycle heat is lost in
a. Cooling coil
b. Condenser
c. Compressor
d. Expansion valve
31. The power factor of AC circuit is
a. R/X
b. R/Z
c. Z/R
d. Zero
32. Silicon controlled output is good if ripple factor is
a. Switch
b. Transformer
c. Amplifier
d. None of above
33. The rectifier output is good if ripple factor is\
a. More
b. Less
c. Constant
d. None of above
34. Protective relays can monitor large AC current by means of
a. Current transformer
b. Potential transformer
c. Micro transformer
d. None of above
35. The combines AM of two similar batteries connected in parallel is:
a. halved
b. doubled
c. remain constant
d. none of above
36. The current in circuit having 5 V EMI source and 10 Ohm resistance is:
a. 2 Amp
b. 50 Amp
c. 5 Amp
d. ½ Amp
37. The chopper is a device to change
a. Voltage
b. Current
c. Frequency
d. None of these
38. The power consumption, in case of centrifugal loads (like pump, fan, blower etc) is proportional to:
a. speed
b. square of speed
c. cube of speed
d. none of these
39. Which of these need to be measured after rewinding the motor:
a. no load current
b. air gap
c. winding resistance
d. all of the above
40. Five percent increase in supply frequency will change the synchronous speed of motor by:
a. -5%
b. +5%
c. -10%
d. +10%
41. Which of the following is the best inverter?
a. square wave inverter
b. sine wave inverter
c. pure sine wave inverter
d. triangular wave inverter
42. For driving a motor in a tape recorder or record player, the motor used is generally:
a. a synchronous motor
b. a hydraulic motor
c. an induction motor
d. a dc series motor
43. The DC motor starter used with a constant speed shunt motor is:
a. 2 point starter
b. 3 point starter
c. 4 point starter
d. 5 point starter
44. A commutator in a DC motor converts
a. AC to DC
b. DC to AC
c. Both AC to DC and DC to AC
d. None of these
45. Two transformers running in parallel will share the load according to their:
a. leakage reactance
b. pu impedance
c. efficiency
d. rating
46. The size of the Earth Wire is determined by:
a. the ampere capacity of the service wires
b. the atmospheric conditions
c. the voltage of service wires
d. none of these
47. The function of lightning arrester is:
a. to limit the short circuit fault current
b. to provide path to high voltage surge to earth
c. to reduce arcing
d. none of these
48. Surge protector provide:
a. high impedance to normal voltage
b. low impedance to surge
c. both (a) and (b)
d. none of these
49. Earthing is necessary to give protection against
a. voltage fluctuation
b. overloading
c. danger of electric shock
d. high temperature of conductors
50. The primary function of fuse is to
a. protect the appliance
b. open the circuit
c. prevent excessive current
d. protect the line
