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Category: BHEL Computer Science Question Paper

BHEL Exam Paper – Computer Science Question Paper

BHEL Exam Paper – Computer Science Question Paper

1. Which one of the following is provided by a data dictionary ?
(A) User data
(B) Functional data
(C) Database structure data
(D) Sorted data

2. Which one of the following is a direct benefit of databse normalization ?
(A) higher query processing efficiency
(B) smaller number of tables
(C) reduced I/O for most queries
(D) reduced data redundancy

3. The ability to modify the conceptual schema without causing any change to the application program is known as :
(A) Physical data independence
(B) Logical data independence
(C) External data independence
(D) Static data

4. A field or a combination of fields that has a unique value is called :
(A) Secondary key
(B) Foreign key
(C) Primary key
(D) Alternate key

5. Relational operator that yields all values from all rows in a table is known as
(A) difference
(B) product
(C) select
(D) project

6. Referential integrity controls relationships between :
(A) attributes in a table
(B) operations of an object
(C) instances of a class
(D) tables in a database.

7. What will be suitable criteria that should be entered for a query to search for Employee Names beginning with M ?
(A) Start with M
(B) Like M
(C) Like ?M??
(D) Like ?M*?

8. What rows will this select statement return ?
SELECT * FROM products WHERE ordernumber > = 1000
(A) All rows in the products table whose order number is greater than or equal to 1000
(B) All rows in the products table whose order number is less than or equal to 1000
(C) The first 1000 rows of the product table
(D) All rows in the products table whose order number is greater than 1000

9. A television broadcast is an example of ______transmission.
(A) Simplex
(B) half-duplex
(C) full-duplex
(D) automatic

10. ______ is the protocol suite for the Internet which we use presently :
(A) TCP/IP
(B) NCP
(C) UNIX
(D) ACM

11. _______ switching is well suited for voice communication while______ switching is better suited for data and other non-voice communication.
(A) Message; circuit
(B) Circuit; message
(C) Packet; circuit
(D) Circuit; packet

12. Forty-five physical channels link________devices arranged in a mesh topology.
(A) NINE (9)
(B) TEN (10)
(C) FORTY (40)
(D) FORTY-FIVE (45)

13. The most frequently used UTP connector is _______ .
(A) category 5 connector
(B) EIA 232
(C) RJ45
(D) JR45

14. The natural mask for class C IP address is _______ .
(A) 255.255.255.0
(B) 255.255.0.0
(C) 255.0.0.0
(D) 255.255.255.255

15. The Internet began as an experimental network called
(A) Intranet
(B) ARPANET
(C) ARPA
(D) DoDNET

16. Clock speed is measured in
(A) Bits per second
(B) Baud
(C) Bytes
(D) Hertz

17. Cache memory enhances
(A) Memory capacity
(B) Memory access time
(C) Secondary storage capacity
(D) Secondary storage access time

18. A user complains that he has created a shell script ?myuse? that will report his usage of disk space by a directory in UNIX, but when he executes the script he only receives the message : myuse : cannot execute. What is the probable cause of the error describedabove ?
(A) The file ?myuse? contains syntax errors
(B) The file ?myuse? cannot be located because the user has not set his PATH properly
(C) The user does not have permission to read his directory
(D) The file mode for the owner of ?myuse? is not executable.

19. Three players A, B, C are in a race. A is twice as likely to win as B and B is twice as likely to win as C. Then the probability that B wins =
(A) 1/2
(B) 2/3
(C) 1/3
(D) 2/7

20. In following Java code snippet, what will be the output of following :
int var 1 = 5, var 2 = 7;
System.out.println(?Result=? + var l * var 3);
(A) Result = 35
(B) Result = 57
(C) Result = 3
(D) Error

21. Consider the following segment of a Java program,
int num, alpha = 10;
num = 4;
switch (num)
{
case 3 : alpha++; break;
case 4 :
case 6 : alpha = alpha + 3;
case 8 : alpha = alpha + 4; break;
default : alpha = alpha + 5;
}
System.out.println (alpha);
What will the output be when the above segment is executed as a program ?
(A) 15
(B) 16
(C) 17
(D) 18

22. The region of memory sufficiently large to hold all pixels of the display is called a
(A) Frame buffer
(B) RAM
(C) ROM
(D) Cache Memory

23. Which of the following statements is correct regarding Bitmap images ?
(A) They are based on lines and curves
(B) They are best for real-world images like Photography and Painted pictures
(C) They have a small data size
(D) One does not need to compress the file for transferring.

24. ???? is a process model used to show the flow of data through a system and the work or processing performed by the system :
(A) Document Flow Diagram
(B) Data Flow Diagram
(C) Entity Relationship Diagram
(D) Use Case Diagram.

25. Consider the code snippet given below :
& lt H1 & gt Hello BIT & lt H1 & gt

Which of the following is correct in relation to the above code snippet ?
(A) Hello BIT is displayed as the output with H1 font.
(B) Hello BIT ; is displayed as the output with H1 font.
(C) ; is displayed as the output with default font.
(D)Hellow BIT is displayed as the output.

26. When you are creating a structure in C/C++, you need to use the keyword
(A) structure
(B) object
(C) struct
(D) record

27. 54__7 = 5. Which arithmetic operator can replace the blank to make the statement correct ?
(A) ?
(B) /
(C) %
(D) *

28. In C++, if a catch statement is written to catch exception objects of a base class type, it can also catch all ______ derived from that base class.
(A) Exceptions for objects
(B) Objects of classes
(C) Arguments
(D) Errors

29. The design of classes in a way that hides the details of implementation from the user is known as :
(A) Encapsulation
(B) Information Hiding
(C) Data Abstraction
(D) Reusability

30. Can two classes contain member functions with the same name ?
(A) No.
(B) Yes, but only if the two classes have the same name
(C) Yes, but only if the main program does not declare both kinds
(D) Yes, this is always allowed.

31. What standard include file is needed to use the exit ( ) function ?
(A) None
(B) Stdlib.h
(C) stdio.h
(D) std.h

32. The processing speed of different computers is compared using :
(A) RPM
(B) GHz
(C) MIPS
(D) CPS

33. Who is associated with the development of ?C? language ?
(A) Niklaus Wirth
(B) Donald Knuth
(C) Dennis M Ritchie
(D) Charles Babbage.

34. Boolean expression for NAND gate with two inputs x and y can be written as :
(A) x ? y
(B) x + y
(C) x + y
(D) xy + xy

35. Two?s complement of 1011.01 is :
(A) 0100.10
(B) 0100.11
(C) 1011.10
(D) 0100.01

36. A friend function can be used to :
(A) avoid arguments between classes
(B) allow access to classes whose source code is unavailable
(C) allow one class to access an unrelated class
(D) increases the versatility of an overload operator

37. In TCP, which layer is not present ?
(A) physical layer
(B) data link layer
(C) transport layer
(D) session layer

38. The digit F in Hexadecimal system is equivalent to ________ in decimal system.
(A) 16
(B) 15
(C) 17
(D) 8

39. The output of a______gate is only 1 when all of its inputs are 1 :
(A) NOR
(B) XOR
(C) AND
(D) NOT

40. 110012?100012 =
(A) 10000
(B) 01000
(C) 00100
(D) 00001

41. Which is correct :
(A) A.A=0
(B) A+1=A
(C) A+A=A?
(D) A?.A? = 0

42. The basic storage element in a digital system is
(A) flip flop
(B) counter
(C) multiplexer
(D) encoder

43. AB + AB? =
(A) A
(B) B
(C) 1
(D) 0

44. In UNIX, which command is used to sort the lines of data in a file in reverse order
(A) sort
(B) sh
(C) st
(D) sort ?r

45. The commonly used UNIX commands like date, ls, cat etc. are stored in
(A) /dev directory
(B) /bin directory
(C) /tmp directory
(D) /unix directory
BHEL Placement Paper
BHEL Placement Paper – Electronics & Electrical

1. When a inductive coil connected to a 200 V, 50Hz ac supply with 10A current flowing through it dissipates 1000 watts then which of the following will have least value in ohms
a.) Resistance
b.) Reactance
c.) Impedance
d.) None

2. Oscillator crystal are made of ?
a.) Silicon
b.) Germanium
c.) Quartz
d.) None

3. For small size, high frequency coils, the most common core material is-
a. )Air
b. )Ferrite
c.) Powdered ion
d.) Steel

4. The Q of a radio coil ?
a.) is independent of frequency
b.) increases monotonically as frequency increases
c.) decreases monotonically as frequency increases
d.) increases upto a certain frequency and then decreases beyond that frequency

5. A superconductor is a ?
a.) A material showing perfect conductivity and Meissner effect below a critical temperature
b.) A conductor having zero resistance
c.) A perfect conductor with highest di-magnetic susceptibility
d.) A perfect conductor which becomes resistance when the current density through it exceeds a critical value

6. When an inductor tunes at 200 KHz with 624 pF capacitor and at 600 KHz with 60.4 pF capacitor then the self capacitance of the inductor would be ?
a) 8.05 pF
b) 10.05pF
c.) 16.01pF
d.) 20.01pF

7. Sparking occur when a load is switched off because the circuit has high ?
a.) Inductance
b.) Capacitance
c.) Resistance
d.) None

8. Sparking between contacts can be reduced by inserting a ?
a.) Resistance in the line
b.) Capacitor in series with contacts
c.) Capacitor in parallel with contacts
d.) None

9. amplifier of an A.M. receiver is normally biased in ?
a.) Class ?A?
b.) Class ?b?
c.) Class ?C?
d.) None

10. The value of gate voltage for the operation of enhancement of only N channel MOSFET has to be ?
a.) High positive
b.) High negative
c.) Low positive
d.) Zero

11. The input gate current of a FET is ?
a.) a few microamperes
b.) negligibly small
c.) a few milliamperes
d.) a few amperes

12. A step recovery diode ?
a.) has on extremely short recovery time
b.) conducts equally well in both directions
c.) is mainly used as a harmonic generator
d.) is an ideal rectifiers of high frequency signals

13. In order to get maximum undistorted output signal from CE amplifier with VCC 10V, the value of VCE (Q) should be approximately-
a.) 0.1V
b.) 5V
c.) 10V
d) V

14. In a FET the electrode, which corresponds to collector in bipolar transistor, is ?
a.) source
b.) drain
c.) gate
d.) none

15. The device which acts like an NPN and a PNP transistor connected base to base and emitter to collector is ?
a.) Triacb
b.) UJT
c.) Diac
d.) SCR

16. A typical optical fibre has ?
a.) High refractive index core and low refractive index cladding
b.) Low refractive index core and high refractive index cladding
c.) Both a and b
d.) None

17. The circuit symbol for a GTO is

18. Which of the following statement is true about two wattmeter method for power measurement in three phase current ?
a.) power can be measured using two wattmeter method only for star connected three phase circuits.
b.) when two meter show indentical readings, in the power factor is 0.5.
c.) when power factor is unit, one of the wattmeter reads zero
d.) when the reading of the two wattmeters are equal but of opposite sign, then the power factor is zero

19. In the lattice network, the value of R for the maximum power transfer to the load ?
a.) 5
b.) 6.5
c.) 8
d.) 9

20. The approximate thickness of the radome wall should be ?
a.) l
b.) l/4
c.) l/2
d.) l/8

21. A relatively permanent information is stored in
a. ) ROM
b.) RAM
c.) PROM
d.) Volatile memory

22. The electric field line and equipotential lines-
a.) Are parallel to each other
b.)Are one and same
c.) Cut each other orthogonally
d.)Can be inclined to each other at any angle

23. The directions of and in TEM mode transmission line with respect to the direction of propagation are-
a.) Both and are transverse to the direction of propagation
b.) is and are transverse and h has a component in the direction of propagation
c.) is entirely transverse and has a component in the direction of propagation
d. ) is entirely transverse and has a component in the direction of propagation

24. For a lossy transmission line short circuited at the receiving end, the input impedance is given by (When Z0 is the characteristic impendence g is the propagation constant and L is the length of the line .When two equal positive point charges are placed along X- axis at X1 and ?X1 respectively then the electric field vector at a point P on the positive Y-axis will be directed-
a.) In the +x direction
b.) In the ?x direction
c. ) In the +y direction
d.) In the ?y direction

25. Joule/coulomb is the unit of ?
a.) Electric field potential
b.) Potential
c .) Charge
d.) None of the above
BHEL Candidate Experiences

BHEL Mechanical Engineering Paper
I attended the BHEL Engineer Trainee written test in Mechanical stream. They conducted for four branches in Engineering: Comp sci, ECE, EEE and Mechanical. In Mechanical Branch there were a total of 240 questions. 120- Technical questions in Mechanical Engineering. 120- General Aptitude questions. (Quantitative Aptitude, Reasoning Ability, Logical thinking, English usage).
The questions were mainly asked in
· Thermodynamics
· Engineering Mechanics
· Theory of machines
· Production tech
If you are thorough with your subject, you can really do well in this session.
[One Mark for correct answer, 1/5th for wrong answer. Five choices were given] Some questions which i remember are :
1)Unit of Entropy (J/kg K or kJ/kg K)?
2)A mass of 100kg is falling from a height of 1 m and penetrates the sand into for 1 m. What is the resistance force given by sand?
3)Ratio of specific heats of air ? (1.41)
4)A body weighs 3 kg in air. If it is submerged in a liquid, it weighs 2.5 kg. What is the specific gravity of the liquid ?
5)Two cars travel in same direction at 40 km/hr at a regular distance. A car comes in a opposite direction in 60km/hr. It meets each car in a gap of 8 seconds. What is the distance between them?
6)A simple problem involving in hoops stress. For sphere: M= [3/2]*p*V* [density of pressure vessel material/Maximum working stress it can tolerate] For Thin walled pressure walls: Hoops stress or stress in the radial direction =p*r/2t?
7) A problem in force calculation in a body moving in a inclined surface?
8)Composition of bronze?
ans. Copper+zinc.
9) Composition of stainless steel.?
ans. iron+ chromium+ nickel+ carbon.
10) CI is manufactured in which process?
ans. cupola process
11)What percentage of carbon is preset in pig iron?
ans. 4.5 to 6%.
12)Water is available at 10m height. What is the pressure available?
ans= pressure=density*g*height;
p=1000*9.81*10;
p=98100N/m2.
13)What will happen if the speed of the centrifugal pump doubles?
14)The unit eV is widely used in ?
ans. Nuclear and atomic physics.
15)What will happen to the resistance, when the diameter of the conductor is doubled?
16)The power comsumed by a electrical device is 1000W at 250V, What is the resistance in the device?
ans. Power= Voltage*current,
Current=Power/Voltage,
Current,I=1000/250=4
amps. V=IR,
Therefore R=250/4=62.5 ohms.
17)Why DC current is not used in transformer?
18)On what principle the sonar/ radar works?
19)Bending moment diagram for the UDL is in what shape?
20)Function of the distributor in petrol vehicles?
ans. Spark timing.
21)Which is not present in CI engines?
ans. carburrettor.
22)What will happen if one cylinder recieves more amount of fuel spray from injectors than other injectors?
23)Purpose of draft tube in hydraulic turbines?
ans. The purpose of a draft tube is toconvert some of the kinetic energy of the flow from the runner (the rotating part of the turbine) intopressure energy and thereby increase the efficiency ofthe hydro power turbine.
24)What is the effect or reheater in the gas turbine?
The advantage of reheater is significantly increased thrust; the
disadvantage is it has very high fuel consumption and inefficiency.
25)Problems involving with fricition coefficient.
26)Factor of safety = Yeild stress/Working stress.
27)Which is the example of non parallel power transmission (Universal coupling)?
28)For perpendicular shafts worm gear is used?
29)A planet gear with 25 teeth is meshed with a sun gear of 100 teeth. Both are connected using a arm. How many rotations are needed for planet gear to complete one rotation around the sun gear?
30)What is equivalent spring constant for spring in parallel?
31) Some questions was asked related to boundary layer and vortex flow.
32) 5 questions were asked in PERT, Process planning, Product planning, Break even analysis.
33)How are tungsten and sintered composite materials are machined?
(Electro Discharge Machining, EDM)
General Apptitude:
very easy. There are 120 questions .
English:
Detect the words with wrong spellings (5 questions).
Fill in the blanks with appropriate words(5 questions).
Two reading comprehensions were given(10 questions).
Find the error in the sentence (8 questions).
Reasoning:
Seating arrangement problems.
Find the relation between them.
Quantitative ability:
50% of the questions are from basic geometry .
Remaining were very general and easy. But many questions are there that’s y you should consider time factor and be quick.

BHEL Previous Paper

1. Critical load acting axially on a long column
Ans: (pi)2*E*I/L2

2. Relation between moment of area and radius of gyration
Ans: I=AK2

3. Cup shaped components are produced using which operation
Ans: drawing

4. A sheet of Al alloy having 2mm thickness is welded using which process
Ans: TIG

5. Two gears having teeth 18 and 40 and center distance 56?what is the module?

6. In thick cylinders, which of the following is true[*S stands for sigma*] (a) St>Sr (b) St=Sr (c)St

7. In a plane stress condition, if the centre of Mohr?s circle coincides with the origin then which is true? ?.the relation between Sx and Sy is asked

8. Lame?s theorem?.F1/sinA=F2/sinB=F3/sinC

9. Young?s modulus value for steel=200Gpa

10. Thermal conductivity of silver=400w/m0K

11. Fouling factor formula??F.F =1/Udirty-1/Uclean

12. Relation between notch sensitivity factor and theoretical stress concentration factor

13. Effectiveness of heat exchanger definition

14. Reynolds?s number formula

15. Clinical thermometer is which order system ?.0,1,2, or 3

16. Piezometric transducer is used to find which signals?static or?. dynamic

17. Peclet number formula=Re*Pr

18. Radiation energy emitted, Eemitted=S*A*T4

19. Which of the following is not related to CI engine
(a) Fuel pump
(b) carburetor
(c)none

20. Two connected in series having stiffness?s K1, K2
Kequivalent=K1*K2/K1+ K2

21. Magnification factor at resonance, MF=1/2zeta

22. Coroili?s component value, =2vw

23. Hooks law holds good upto
(a)elastic point
(b)UYP
(c)LYP
(d)Failure

24. Meshing of two gears fail if
(a)materials are different

25. A beam whose one end is fixed and other is free is
(a)cantilever
(b)ss
(c)Udl
(d)none

26. Deflection at the free end of cantilever =PL3/3EI

27. Rota meter is used to find
(a)flow
(b)velocity
(c)pressure
(d)density

28. Formula for polar moment of inertia of a hollow shaft

29. Formula for logarithmic decrement

30. Metacentric height is the distance between Metacentre and ——–
Ans: Centre of gravity
BHEL Whole Testpaper
Branch:-Electrical
Technical Questions
1.SCR of an alternator is___________________________(Ans :inversely proportional to Xs adjusted in P.U)
2.In Synchronous Impedance method the regulation is__________(Ans: Higher than actual)
3.Thyristor which is in forward blocking method will conduct if________(Ans:-Positive gate pulse to Cathode)
4.SC test of T/F will give __________( Copper lossers)
5 741 IC is an ____________(OP amp)
6.For ideal Op amp _________(Zin =infinite and Zout = 0)
7.S^2-5s+20/S^2+5S-20_______________________( All pass or Band Eliminator or….
8 Memory allocated for LIFO is _____________(Stack)
9.A register which stores the address of the instruction to be executed is___________(Program Counter)
10 MHO relay is a _______( Directional Over current relay)
11. A directional relay has___________ type of characteristics
12 MC is used for __________(measuring DC)
13 A Converter can be operate as inverter if ______________( Ans Full converter (may be) Commutation circuit also)
14 Coupling used when the shafts are not inline___________(Universsal)
15.first Nuclear Power plant in India is ____________(Tarapur)
16 Nuclear and Thermal are used as_________( Base Load plants)
17. Which Plant has max No. of auxillaries___________(Thermal)
18.In T/L to transfer max power______(—)
19. An Cascade amplifier has which type of intermediate stages__________(CE-CB)
20 Syn M working @ UPF if Exc is increased it operates at___________(Lead PF)
21 Current corresponding to max Efficiency in a T/f given Pi and R______________(Sqr Rt of(Pi/R)
22. Input to Stator of I/M is 40 KW slip is 5% then Torque in Syn Watts when Stator Cu losses & Iron losses are Neg________________(38 W)
23 Blocked Rotor Test givs ___________(Cu losses)
24. N type impurity is_______________(Phosporous)
25 An Eg of Semi Conductor____________(Germenium)
26 Cable insulation resistance is ______________(inversely proportional to length)
27. Hand driven tools use_________(Shaded pole induction motor)
28 A Hysteresis Motor runs at ____________( Sync , Sub- Syn & Super Syn Speed)
29 Octal 56 to Binary_______(46)
30 Sinusoidal Pulse width Modulation what can be controlled ________(freq , Volt & Harmonic)
31 A nullator is a _____________(find out)
32 First law of Thermodynamics __________(Q=dU+W)
33 In watches which type of oil is used__________(find out)
34 In shafts for operating at high temp type of lubricant used is ___________(find out)
A couple of questions on Thevenin.
Some questions on Control systems ( Basics)
Some on Alternator and T/f parallel operations( 6 Qs)
Non Technical::
Quant:
Questions on Venn diagrams (10), Percentages-Ratios-averages, Speed and Work , Kinematics, Shares , Time and Distance, Calendars, Geomentry( 20 Q from Basics)…………….
English:
Sentence correction( 5), Vocab(Syn n Ant10 Q), Jumbled sentences (5), RC (5 Q), Spellling Mistakes (5Q)
Reasoning :
Blood relations(2), Odd men out(3), Arrange in proper order (3 Q eg: Plant ,cloth, Yarn, saree, cotton.)Deductions,
For all these topics R.S Agarwal is more than sufficient.
Thats it Folks hope this will help u out …………………….ALL D BEST