BSNL JTO Technical Assistant previous years solved question paper

BSNL JTO Technical Assistant previous years solved question papers of electronics and electrical engineering.. For the preparation of BSNL Exam General Ability -20 marks questions, Basic Engineering-90 Specialisation-90 marks questions. Practice model question papers

1. For reflection co-efficient |r| = 1/2 VSWR is

(A) 2

(B) 3 (Ans)

(C) C

(D) 8

2. Radiation resistance of a half wave dipole is

(A) 73 ? (Ans)

(B) 377 ?

(C) 300 ?

(D) 50 ?

3. Which of the following is not Maxwell’s equation ?

(A) B = ?H

(B) E = D/?

(C) E = J/?

(D) E = ?D (Ans)

4. A medium is called isotropic when

(A) ? is zero

(B) ? is a scalar constant (Ans)

(C) ? = ?

(D) ? = ??

5. Which of the following is not a wide band antenna

(A) marconi (Ans)

(B) helical

(C) rhombic

(D) folded dipole

6. The wave which “lies down and dies” is called

(A) ground wave (Ans)

(B) sky wave

(C) space wave

(D) spherical wave

7. When cathode is positive with respect to anode in an SCR, the number of p-n junction is

(A) 1

(B) 2 (Ans)

(C) 3

(D) 4

8. The impulse response and the excitation function of a linar time invariant causal system are shown in Fig. (a) and (b) respectively. The output of system at t = 2 sec is equal to

(A) 0

(B) 1/2 (Ans)

(C) 3/2

(D) 2

Solution : y (y) = f x (t) h (t – t) dt

Out Put = 1/2 * 2 1/2 = 1/2

9. The initial contents of the 4-bit serial-in-parallel-out right-shift, Shift Register shown in Fig.is 0110. After three clock pulses are applied, the contents of the Shift Register will be

(A) 0000

(B) 0101

(C) 1010 (Ans)

(D) 1111

Solution : 4-bit SIPO

1 XOR (1, 0) = 1 1011

2 XOR (1, 1) = 0 0101

3 XOR (0, 1) = 1 1010

contents will be 1010.

10. Fig. shows the circuit of a gate in the Resistor Transistor Logic (RTL) family. The circuit represents a

(A) NAND

(B) AND

(C) NOR

(D) OR (Ans)

Vi1 Vi2 Vx V0 Q1 Q2 Q3

L L H L OFF OFF ON

L H L H OFF ON OFF

H L L H ON OFF OFF

H H L H ON ON OFF

The circuit represent an OR. Hence choice is d.

11. The logic realized by the circuit shown in Fig.

(A) F = A . C

(B) F = A + C (Ans)

(C) F = B . C

(D) F = B + C

F = does not depend on B.

F = A C + A C = A ? C

12. A Lissajous pattern, as shown in Fig below, is observed on the screen of a CRO when voltage of frequencies fx and fy are applied to the x and y plates respectively. fx : fy is then equal to

(A) 3 : 2

(B) 1 : 2 (Ans)

(C) 2 : 3

(D) 2 : 1

Solution : fx/ff = Points of tangency to vertical line/Points of tangency to horizontal line = 1/2

or fx : fy = 1 : 2

13. In the transistor circuit shown in Fig. below, collector-to-ground voltage is + 20 V. Which of the following is the probable cause of error ?

(A) Collector-emitter terminals shorted

(B) Emitter to ground connection open (Ans)

(C) 10 k ? resistor open

(D) collector-base terminals shorted

Aptitude – General

BSNL PAPER ON JULY,2011 1.Which Sentence is correct:
a.French is known by me.
b.French live in France.
c.France is an European country.
d.Nepolean was a French king.
Ans.b

2.Antonymous of ” OBSOLETE”:
a.Current b. old c. relative d. neutral
ans.a

3.I am agree _ the project.
a. to b. on c. with d. at
ans.a

4.”MY LIFE MY COUNTRY” author’s name:
b.Manmohan Singh
c.Soniya Gandhi
d.Apj Abul Kalam
ans.a

a.koneru hampi
b.s. subrahamanyam
d.kiran gosvami
ans.a

6.J.L. Bayard invented:
a.radio b. telephone c. telegraph d. television
ans.d

7.Simla agreement was done between India and _
a. china b. Nepal c. Pakistan d. Bhutan
ans.c
8. Myanmar is not share its boundary with
a. assam b. mizoram c. Manipur d. nagaland .
Ans.a
9. First “ROUND TABLE CONFRESS” between India & Britain was in:
a. Calcutta b. Delhi c. London d.Peris
ans.c

10. Iron man of India is :
a. Lala lajpat rai
b . subhash Chandra bose
c. sardar vallabhai patel
d . pandit jawahar lal nehru
ans.c
11.WORLD TELECOMMUNICATION DAY is on:
a. may 17 b. july 21 c. june 26 d. augast 22
Ans.a

12.Greenhouse Effect is caused by:
a. Carban di oxide b. sulphar di oxidem c. Carban mono oxide d. oxyzen
ans.a
13.Oldest IIT is:
a.IIT, Bombay b. IIT, Guwahati c. IIT, delhi d. IIT,Khadakpur
ans.d
14. Kalpana-I satellite is launched basically for:
a.Distance education
c.Metrological purpose
d.Travel & science
ans.c
15. Radio Waves transmission & receiving phenomenon invented by:
16. HYNYANIKA was a type of:
17. Following Shaded parts of country is producer of:
a. Jute b. Rubber c.tea d.coffee

18 What is the term: “IMMUNOLOGY”
19 coming soon.
Placement Paper
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SAMPLE BITS OF BSNL DGM PART-A , ECONOMICS. BSNL Management trainee,JTO officer recruitment test procedure and previous years solved questions with answers

Q) Positive economics explains economic phenomena according to?

Ans) Their causes and effects
Q) A positive statement is based on facts. A normative statement involves________________?

Ans) ethical values.
Q) Microeconomics is sometimes referred to as________________?

Ans) Price Theory.

Q) In a Free market economydemand and supply determine_______________?

Ans)The allocation of resources.

Q) In a Free Market economy If demand for a product is high and supply is less than the demand, its price will________________?

Ans) Increase.

Q) In _________________ economy consumers and producers make their choices based on the market forces of demand and supply, as reflected in prices.

Ans) Market

Q) In a market economy Market forces determine the allocation of scarce resources through___________________ mechanism

Ans) the price

Q) A free economy cannot function in________________?

an anarchic situation(not being under control; out of control; eg:”the greatest uncontrolled health problem is AIDS”; “uncontrolled growth)

Q) In a ____________________economy, all the economic decisions, like what to produce, how to produce, and for whom to produce are taken by the government& it has complete control over the economy.

Ans) command

Q) Expand PPC?

Ans) Production possibility curve.

Q) If a point falls inside the Production possibility curve,it indicates?

Ans) Resources are underutilized and there is unemployment in the economy

Q) The outward shift in the PPC represents_______________?

Ans) Growth of the economy.

Q) ____________________do not form part of the PPC in any way?

Ans) Demand-supply analysis (prices, demand & supply)
Candidate-Experiences
BSNL PAPER ON 20TH JULY,2008

1) who is author of “my people my country ?
2) Who is first women grand master in India ?
Ans – S. Vijay Laxmi. (it was not koneru humpy she is youngest GM not First GM)
3) Who is iron Man ?
Ans – Sardar Vallabhai Patel.
4) where was Round Table conference was held ?
Ans – London
5) The branch in which study regarding immunity was done ?
Ans – Immunology.
6) What is HiINIAN ?
Ans -Regarding Buddhas (Some thing like that )
7) There is a Map given shown “KERALA & MEGHALAYA” in that which crop is more asked ?
Ans – I think answer may be Coffee. There is a confusion with TEA.
FPRIVATE “TYPE= PICT; ALT=
8)” Which state not touch the boundary of “Myanmar ”
Ans – Mizoram.
9) Oldest I I T at ?
Ans – Kharagpur.
10) There is a question of ENGLISH sent. .I agree “with” the proposal given by you .
Ans is —- With ( May be )
11) Vitamin “C” found in ?
Ans – Orange & Lemon.
12) Radio Wave was invested by whom ?
Ans – See friend actual answer was “Markoni” but this was not option so correct option is ” Sir . Jagadish Chandra Bose .( Indian)
13) When is world telecom day ?
Ans – 17th May. recently
14) shimala agreement was between ?
Ans-India & Pakistan .
15) which gas is responsible for “Green house Effect”?
Ans- CO2 ( Carbon di oxide)
16)Who invested TV ?
Ans – Beard.
17) There is a 04 English sentence given and we need to choose correct one reg freance & french.
Ans — As per my knowledge is was ” French people live in France”
18) A bunch of island were known ?
Ans – I don’t know please tell me .
19) The anytome of ………( I forgot the word )
Ans – Please tell me .
20) I still not remember the 20th question . This is my challenge to you friend please recall this question & answer of it
Best of luck .;…….!

Placement Paper

Bharat Sanchar Nigam Limited BSNL Technical Assistant- TTA Computer QuestionsElectronics and electrical solved questions for practice, BSNL TTA-Technical Assistant practice questions with answers to learn and practice BSNL TTA- Technical Assistant JTO officers examination collection of solved question papers with detailed explanation and study tips to crack all competitive examinations, BSNL TTA Electrical, Communication, General ability, Basic Engineering questions with answers for practice, BSNL TTA model question papers to learn and practice

BSNL OBJECTIVE TYPE QUESTIONS FOR PRACTICE

Question Bank in Computer Science

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

(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

(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

(c) security commands

(d) code words

39. A factor which might cause an individual to consider using a computer in criminal activities is :

(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
Bharat Sanchar Nigam Limited BSNL Technical Assistant Junior Telecom Officers written test examination question papers, BSNL recruitment examination free solved question papers,BSNL Sample Papers – 2 BSNL free solved sample placement papers

BSNL electronics and electrical questions with answer

1. The output signals amplitudes for I’s and 0’s in an ADM transmission systems are

(A) Fixed and the repetition rate is also fixed

(B) Fixed but the repetition rate is variable

(C) Variable and the repetition rate is also variable

(D) Variable but the repetition rate is fixed (Ans)

2. Microwave link repeaters are typically 50km apart

(A) Because of atmospheric attenuation

(B) Because of Output tube power limitations

(C) Because of the earth’s curvature (Ans)

(D) To ensure that the applied ac voltage is not excessive

3. The amplifier inserted at intervals to amplify the signal and compensate for transmission loss on the cable are called

(A) line amplifier

(B) equalizing amplifiers

(C) comparators

(D) repeaters (Ans)

4. Diversity reception in used to

5. Mark out transferred electron device in the following

(A) BARITT dived

(B) IMPATT dived

(C) Gunn dived (Ans)

(D) step recovery diode

6. In the output of a normal monochrome receiver video detector voltages, which are not found, are

(A) syne

(B) video

(C) sweep (Ans)

(D) sound

7. A transistor is operated as a non-saturated switch to eliminate

(A) storage time

(B) turn-off time (Ans)

(C) turn-on time

(D) delay time

8. Thyristor A has rated gate current of 2 A and thyristor B a rated gate current of 100 mA-

(A) A is a GTO and B is a conventional SCR (Ans)

(B) B is a GTO and A is a conventional SCR

(C) B may operate as a transistor

(D) none of the above

9. Mark old the correct statement for Cycloconverters

(A) step-down Cycloconverter (CC) works on natural commutation (Ans)

(B) step up CC requires no forced commutation

(C) load commutated CC works on line commutation

(D) none of the above

10. Rotors used in a two-phase ac servomotor is

(A) solid iron motor

(B) squirrel cage rotor

(C) drag cup rotor

(D) both (B) and (C) (Ans)

11. Major advantage of TWT over a klystron lies in its

(A) higher bandwidth

(B) higher output

(C) higher frequency

(D) higher gain (Ans)

12. The Boolean expression for the shaded area in the given Venn diagram is

(A) AB + BC + CA (Ans)

_ _ _
(B) ABC + ABC + ABC

(C) ABC + ABC

(D) None of the options

13. A lag compensator is basically a

(A) high pass filter

(B) band pass filter

(C) low pass filter

(D) band elimination filter (Ans)

14. In flowchart which figure represents process like subroutine

(A)

(B)

(C)

(D)

(Ans)

15. The storage and retrieval of data on stacks should follow sequence

(A) last in first out (Ans)

(B) first in first out

(C) random in random out

(D) none

16. While executing program microprocessor checks INTR line clearing

(A) each instruction (Ans)

(B) after interval of two instruction

(C) after a subroutine

(D) at the end of program

17. In which error check technique of data communication 2’s complement of all bytes of data is transmitted with data

(A) Even parity

(B) odd parity

(C) check scans (Ans)

(D) cyclic redundancy

18. Program execution hierarchy decides which operator

(A) is most important

(B) is used first (Ans)

(C) is fastest

(D) operators on largest number

19. (375)10 = (—-)8

(A) 550

(B) 557

(C) 567 (Ans)

(D) 577

20. To obtain 2048 * 8 memory using 128 * 8 memory chip how many IC required

(A) 2

(B) 4

(C) 8

(D) 16 (Ans)

21. A Decimal number 17 can be converted in binary, the binary number will be

(A) 10001 (Ans)

(B) 01110

(C) 00111

(D) 11100

22. Is the Universal logic gate

(A) AND

(B) OR

(C) NAND (Ans)

(D) X-OR

23. A monostable state in multivibrator means

(A) which returns itself to its single stable state (Ans)

(B) the state used only once in circuit

(C) the state of circuit can not get changed

(D) the state of circuit always changing

24. For designing binary counter which flip flop is preferred

(A) T FF

(B) SR FF

(C) D FF (Ans)

(D) JKFF

25. The HV anode supply for the picture tube of TV receiver is generated in the

(A) mains transformer

(B) vertical output stage

(C) horizontal output stage (Ans)

(D) horizontal deflection oscillator

26. The frequency range for satellite broad casting is

(A) 30 MHz – 300 MHz

(B) 30 MHz – 3 GHz

(C) 3 GHz – 30 GHz (Ans)

(D) 30 GHz – 300 GHz

27. Iris is used to

(A) Over come power loss

(B) Over come bending effect

(C) Over come mismatch error (Ans)

(D) Over come twist effect

28. In schotty barrier diode current flows because of

(A) Majority carriers

(B) Minority carriers (Ans)

(C) Majority and minority carriers

(D) None

29. Which antennas are used in microwave communication

(A) long wave antennas

(B) Rhombic antennas

(C) Paraboloidal antennas (Ans)

(D) All of above

30. Among translator and time of sight system capacity

(A) Of translator is more (Ans)

(B) Of line of sight is more

(C) Having equal capacity

(D) No relation such as

31. No of T- state required for memory read or write operation

(A) 2

(B) 3 (Ans)

(C) 4

(D) 6

32. In data transfer operation which flag get affected

(A) 3140 flog

(B) carry flog

(C) sign flog

(D) none (Ans)

33. Aswan Dam is located in

(A) Egypt (Ans)

(B) Libya

(C) Sudan

(D) Iran

34. Ghana Birds sanctuary is in the state of

(A) Rajasthan (Ans)

(D) Maharashtra

35. Dry ice is

(A) Frozen carbon monoxide (Ans)

(B) Frozen carbon dioxide

(C) Frozen ammonia

(D) None of these

36. East flower river of India is

(A) Cauvery (Ans)

(B) Sone

(D) Tapti

37. The total length of the great wall of China is

(A) 1,400 miles (Ans)

(B) 1,500 miles

(C) 1,300 miles

(D) 1,400 miles

38. Deficiency of vitamin C may result in

(A) beriberi

(B) night blindness

(C) dermatitis

(D) Scurvy (Ans)

39. Bharat Shah a film financier was granted bail by Supreme Court after a period of

(A) 11 months

(B) 2 years

(C) 18 months

(D) 15 months (Ans)

40. Indian local time is based on

(A) 800 E longitude

(B) 82 1/20 E longitude (Ans)

(C) 1100 E longitude

(D) 250 E longitude

41. The two days Shiv Shena Mahashivir of 2002 started at Shirdi on

(A) 9th April 2002 (Ans)

(B) 10th April 2002

(C) 8th April 2002

(D) 11th April 2002

42. Which one is a good preservative of food ?

(A) Spirit

(B) Formaldehyde (Ans)

(C) Sugar

(D) None of the above

43. His handwriting was not —- so I could not read his note

(A) attractive

(B) eligible

(C) clear

(D) legible (Ans)

44. They started to —- people into the theatre only at six

(A) enter

(C) follow

(D) accept

45. I told him to buy things that are lasting (Give the appropriate synonym of the underlined word).

(A) ending

(B) ordinary

(C) durable (Ans)

(D) cheap

46. Give the word which is most opposite in meaning of the word ‘evident’

(A) doubtful (Ans)

(B) unimportant

(C) disagreed

(D) understood

47. I expressed by disagreement — him on that issue

(A) between

(B) with (Ans)

(D) for

48. ‘Sugarbowl’ of the world is

(A) India

(B) Cuba (Ans)

(C) Brazil

(D) USA

49. Palk strait separates

(A) India and Srilanka (Ans)

(B) India and Burma

(C) Britain and France

(D) Malaysia and Sumatra

50. The minimum number of atoms in a molecule of an element are

(A) 1 (Ans)

(B) 5

(C) 2

(D) 10

51. Tides in the sea are caused by

(A) Effect of sun

(B) Effect of moon

(C) Combined effect of moon and sun (Ans)

(D) Gravitational, centrifugal and centripetal forces

52. The Bar Council of India decided to close over law colleges across the country for their failure to maintain minimum teaching standard. There number is

(A) 140

(B) 200

(C) 150

(D) 100 (Ans)

53. When a four terminal T network is inserted between a source and load resistance as shown in figure then the resistance seen by the source remain the same with or without the four terminal block when R is

(A) 5 O

(B) 10 O

(C) 15 O (Ans)

(D) 20 O

54. The output Y of the circuit in the given Fig. is

(A) (A + B) C + DE (Ans)

(B) AB + C (D + E)

(C) (A + B) C + D + E

(D) (AB + C) . DE

55. See the circuit shown and choose the correct option

(A) Only red will glow (Ans)

(B) Only green will glow

(C) Both red and green will glow

(D) Neither red nor green will glow
Placement Paper
Bharat Sanchar Nigam Limited BSNL Technical Assistant Junior Telecom Officers written test examination question papers, BSNL recruitment examination free solved question papers,BSNL Sample Papers – 2 BSNL free solved sample placement papers

BSNL electronics and electrical questions with answer

1. As the drain voltage is increased for a junction FET in the pinch off region then the drain current __

(A) Becomes zero

(B) Abruptly decreases

(C) Abruptly increases

(D) Remains constant (Ans)

2. When the gauge factor of a strain gauge is 2, stress is 1050 kg/cm2, Y = 2.1 * 106 kg/cm2 and R is 100 ohms then the value of DR will be __

(A) 2 W

(B) 3 W

(C) 4 W

(D) 1 W (Ans)

3. Telemetering is a method of ___

(A) Counting pulses sent over long distances

(B) Transmitting pictures from one place to another

(C) Transmitting information concerning a process over a distance (Ans)

(D) None

4. Time constant of an RC ciruit increases if the value of the resistance is

(A) Increased (Ans)

(B) Decreased

(C) Neither a nor b

(D) Both (A) and (B)

5. The location of lighting arrestor is

(A) Near the transformer (Ans)

(B) Near the circuit breaker

(C) Away from the transformer

(D) None

6. For the n-type semiconductor with n = NP and P = p2/ND the hole concentration will fall below the intrinsic value because some of the holes

(A) drop back to acceptor impurity states

(B) drop to donor impurity states

(C) Virtually leave the crystal

(D) recombine with the electrons (Ans)

7. When an RC driving point impedance function has zeros at s = -2 and s = -5 then the admissible poles for the function would be

(A) s = 0 ; s = -6

(B) s = 0 ; s = -3 (Ans)

(C) s = 0 ; s = -1

(D) s = 0 ; s = -4

8. When a sample of germanium and silicon having same impurity density are kept at room temperature then

(A) Both will have equal value of resistivity

(B) Both will have equal value negative resistivity

(C) Resistivity of germanium will be higher than that of silicon

(D) Resistivity of silicon will be higher than that of germanium (Ans)

9. When a signal of 10 mV at 75 MHz is to be measured then which of the following instrument can be used

(A) VTVM

(B) Cathode ray oscilloscope (Ans)

(C) Moving iron voltmeter

(D) Digital multimeter

10. When a piece of copper and another of germanium are cooled from room temperature to 8000 K then the resistance of

(A) Each of them increases

(B) Each of them decrease

(C) Copper increases and germanium decreases

(D) Copper decreases and germanium increases (Ans)

11. One of the following, which is not a transducer in the true sense, is

(A) Thermocouple

(B) Piezoelectric pick up

(C) Photo-Voltaic cell

(D) LCD (Ans)

12. When a transistor is required to match a 100 W signal source with a high impedance output circuit then the connection that would be used is

(A) Common base (Ans)

(B) Common collector

(C) Common emitter

(D) Emitter follower

13. In a JFET gates are always __

(A) forward biased

(B) reverse biased (Ans)

(C) unbiased

(D) none

14. The main factor which differentiate a DE MOSFET from an E only MOSFET is the absence of ___

(A) insulated gate

(B) electrons

(C) channel (Ans)

(D) P-N junction

15. An SCR conducts appreciable current when-

(A) Anode and gate are both negative with respect to cathode

(B) Anode and gate are both positive with respect to cathode (Ans)

(C) Anode is negative and gate is positive with respect to cathode

(D) Gate is negative and anode is positive with respect to cathode

16. Silicon is not suitable for fabrication of light emitting diodes because it is

(A) An indirect band gap semiconductor

(B) A direct band gap semiconductor (Ans)

(C) A wide band gap semiconductor

(D) A narrow band gap semiconductor

17. An average responding rectifier type electronic ac voltmeter has its scale calibrated in terms of the rms value of a sine wave, when a square wave voltage of peak magnitude 100 V is measured using this voltmeter then the reading indicated by the meter, will be

(A) 111 V (Ans)

(B) 100 V

(C) 90.09 V

(D) 70.7 V

18. Which one of the following conditions for Z parameters would hold for a two port network containing linear bilateral passive circuit elements__

(A) Z11 = Z22

(B) Z12 Z21 = Z11 Z22

(C) Z11 Z12 = Z22 Z21

(D) Z12 = Z21 (Ans)

19. The number of lobes on each side of a 3 resonant antenna is

(A) 3

(B) 6 (Ans)

(C) 2

(D) 1

20. A yagi antenna has a driven antenna-

(A) Only

(B) With a reflector

(C) With one or more directors

(D) With a reflector and one or more directors (Ans)

21. For an elliptically polarized wave incident on the interface of a dielectric at the Brewster angle then the reflected wave will be

(A) Elliptically polarized

(B) Linearly polarized (Ans)

(C) Right circularly polarized

(D) Left circularly polarized

22. A transmission line of characteristic impedance Z0 = 50 ohms, phase velocity VP = 2 * 108 m/s at = 1 m is terminated by a load ZL = (30 -j40) ohms. The input impedance of the line for a frequency of 100 MHz will be

(A) (30 + j40) ohms

(B) (30 – j40) ohms (Ans)

(C) (50 + j40) ohms

(D) (50 – j40) ohms

23. Maxwell’s loop current method of solving electrical networks

(A) uses branch currents

(B) utilizes Kirchhoff’s voltage law (Ans)

(C) is confined to single-loop circuits

(D) is a network reduction method.

24. While calculating Rth, constant current sources in the circuit are

(A) replaced by opens (Ans)

(B) replaced by ‘shorts’

(C) treated in parallel with other voltage sources

(D) converted into equivalent voltage sources

25. In the circuit shown, the switch closes at t = 0. The voltage across 4µF capacitor in ideal condition

(A) 0

(B) 16 V (Ans)

(C) 15 V

(D) 24 V

26. Radiation resistance of a half wave folded dipole is

(A) 72 O

(B) 144 O

(C) 288 O (Ans)

(D) 216 O

27. When a carrier wave is modulated at 100% it’s power is increased by

(A) 100%

(B) 15%

(C) 50% (Ans)

(D) 0%

28. On a clear sky day, the atmospheric ratio noise is strongest

(A) During morning house

(B) Around mid-day

(C) During nights (Ans)

(D) In the afternoon.

29. TV broadcasting system in India is as per CCIR

(A) System B (Ans)

(B) System I

(C) System M

(D) System X

30. For the safety measurement of the internal resistance of a 25-0-25 µA meter, a laboratory multimeter whose sensitivity is equal to _.

(A) 1 k ohm/volt can be used

(B) 10 k ohm/volt can be used

(C) 100 k ohm/volt can be used

(D) 200 k ohm/volt can be used (Ans)

31. In order to measure moisture in wood the most suitable method is

(A) Electrical conduction (Ans)

(B) Electrical-capacitive

(D) Equilibrium-moisture vs humidity

32. The flow rate of electrically conducting liquid without any suspended particle cannot be measured by

(A) turbine flow meters

(B) electromagnetic flow meters

(C) ultrasonic flow meters

(D) thermistor based heat loss flow meters (Ans)

33. The most useful transducer for displacement sensing with excellent sensitivity, linearity and resolution is

(A) an incremental encoder

(B) an absolute encoder

(C) LVDT (Ans)

(D) a strain gauge

34. When variable reluctance type techometer has 150 teeth on the rotor and the counter records 13,500 pulses per second then the rotational speed will be

(A) 4800 rpm

(B) 5400 rpm (Ans)

(C) 6000 rpm

(D) 7200 rpm

35. In the RF amplifier stage cascade (CE-CB) amplifier is used because it gives-

(A) Large voltage gain

(B) Low output impedance

(C) Large isolation between the input and the output (Ans)

(D) None of the above

36. Silicon diode is less suited for low voltage rectifier operation because

(A) it can withstand high temperature (Ans)

(B) ensures low PIV of the diodes

(C) ensures lower values of capacitance in the filter

(D) reduces ripple content

37. An amplifier of class A is that in which

(A) Base is biased to cut – off

(B) Ie flows most of the time

(C) Ie flows all the time (Ans)

(D) Vc often raises to Vcc

38. A transistor is in active region when

(A) IB = b IC

(B) IC = b IB (Ans)

(C) IC = IE

(D) IC = IB

39. For coupling purposes in RF amplifier a buffer amplifier is used because it provides-

40. A transistor has CE parameter as hje = 10k O, hre = 20 * 10-4, hse= 100, hoe = 25 µs. The hib for this transistor will be

(A) 100 W

(B) 99.01 W (Ans)

(C) 5m W

(D) 101 kW

(A) 110 MHz

(B) 112 Hz (Ans)

(C) 114 MHz

(D) 120 MHz

42. If RL is shorted out, then VCE will become

(A) OV

(B) VCC – IBRB

(C) Equal to VCC (Ans)

(D) None of the above

43. A dc to dc converter having an efficiency of 80% is delivering 16W to a load. If the converter is generating an output of 200 V from an input source of 20 V, then the current drawn from the source will be

(A) 0.1 A

(B) 0.5 A

(C) 1.0 A (Ans)

(D) 10.0 A

44. On a voltage scale, zero dB m in a 600-ohm system could refer to

(A) 1.732 V

(B) 1.0 V (Ans)

(C) 0.7746 V

(D) 0.5 V

45. One of the following devices which is required in addition in order to measure pressure using LVD is

(A) Strain gauge

(B) Pitot tube

(C) Bourden tube (Ans)

(D) Rotameter.

46. It is required to measure temperature in the range of 13000 C to 15000 C. The most suitable thermocouple to be used as a transducer would be

(A) chromel-constantan

(B) Iron-constantan

(C) chromel – alumel

(D) platinum – rhodium (Ans)

47. In a CSI if frequency of output voltage is fHz, then frequency of input voltage to CSI is-

(A) f

(B) 2f (Ans)

(C) f/2

(D) 3f

48. Identify the type of chipper in the given circuit

(A) Type A chopper

(B) Type B chopper (Ans)

(C) Type C chopper

(D) Type D chopper

49. Maximum value of charging resistance in an UJT associated with-

(A) peak point (Ans)

(B) valley point

(C) any point between peak and valley

(D) after the valley point

50. In a 3 phase full converter, the output voltage during overlap is equal to

(A) zero

(B) source voltage

(C) source voltage minus the inductance drop

(D) average value of the conducting phase voltages (Ans)
Placement Papers
Bharat Sanchar Nigam Limited BSNL Technical Assistant- TTA Electronics and electrical solved questions for practice

BSNL OBJECTIVE TYPE QUESTIONS FOR PRACTICE

1. The electrical conductivity of metals is typically of the order of (in ohm-1 m-1)

(A) 107 (Ans)

(B) 105

(C) 10-4

(D) 10-6

2. There electronic configuration of carbon is

(A) 1s2 2s2

(B) 1s2 2s2 2p6 2s2

(C) 1s2 2s2 2p6

(D) 1s2 2s2 2p2 (Ans)

3. Which law is synonymous to the occurrence of diamagnetism?

(A) Ampere’s law

(B) Maxwell’s law

(C) Coulomb’s law

(D) Lenze’s law (Ans)

4. Which of the following are piezo-electric substances:

1. Barium titanate

(A) 1,2 and 4

(B) 1,3 and 4

(C) 1,2 and 3 (Ans)

(D) 2,3 and 4

5. The temperature below which certain materials are anti-ferromagnetic and above which they are paramagnetic is called

(A) Weiss temperature

(B) Curie temperature

(C) Neel temperature (Ans)

(D) Double point temperature

6. Pure metals generally have

(A) high conductivity and low temperature co-efficient

(B) high conductivity and large temperature co-efficient (Ans)

(C) low conductivity and zero temperature co-efficient

(D) low conductivity and high temperature co-efficient

7. Magnetostriction

(A) induced magnetism

(B) volume changes accompanying (Ans)

(C) rate of magnetisation

(D) rate of loss of magnetism

8. When ne and nh are the electron and hole densities, and µe and µh are the carrier mobilities, the Hall co-efficient is positive when,

(A) nh µh > ne µe

(B) nh µh2> ne µ2e (Ans)

(C) nh µh < µe

(D) nh µh2> ne µ2e

9. Semi-conductor A has a higher band gap than semi-conductor B. If both A and B have the same dimensions, the same number of electrons at a given temperature and the same electron and hole mobilities, then

(A) A has the same number of holes as B

(B) A has a larger number of holes than B (Ans)

(C) A has a less number of holes than B

(D) Any of the above statements at (A), (B) or (C) could be true

10. Which of the following crystallographic defects contributes to electronic defects?

1. Thermal vibration

2. Point defects

3. Line defects

4. Surface defects

Select the correct answer using the codes given below

(A) 1,2 and 3 (Ans)

(B) 2,3 and 4

(C) 1,3 and 4

(D) 1,2 and 4

11. Above the curie temperature, the hysteresis loop of a ferroelectric material can be described by a

(A) parabola

(B) cycloid (Ans)

(C) straight line

(D) point

12. Orientational polarizations is

(A) inversely proportional to temperature and proportional to the square of the permanent dipole moment (Ans)

(B) proportional to temperature as well as to the square of the permanent dipole moment

(C) proportional to temperature and inversely proportional to the square of the permanent dipole moment

(D) inversely proportional to temperature as well as to the square of dipole moment

13. In a piezoelectric crystal oscillator, the oscillation or tuning frequency is linearly proportional to the

(A) mass of the crystal

(B) square root of the mass of the crystal

(C) square of the mass of the crystal

(D) inverse of the square root of the mass of the crystal (Ans)

14. Some of electrons are injected into the interior of a conductor surrounded by an insulator.

The injected electrons will

(A) distribute themselves uniformly

(B) distribute themselves randomly

(C) be confined at the point of injection

(D) travel to the surface of the conductor (Ans)

15. The isotope effect predicts that the super-conducting transition temperature should be proportional to (M is the atomic mass)

(A) M

(B) 1/M

(C) 1/vM (Ans)

(D) vM

16. Consider the following statements : In the case of diamagnetic materials, the magnetic susceptibility is

1. Positive

2. Negative

3. Independent of temperature

4. Inversely proportional to temperature of these statements

(A) 1 and 3 are correct

(B) 2 and 3 are correct (Ans)

(C) 1 and 4 are correct

(D) 2 and 4 are correct

17. A small saw cut is made in a permanent magnet of toroidal shape. Which of the following are true for H0, if H0 is the magnetic field in the air-gap and Hi is that inside the magnet?

1. H0 < ?Hi?

2. H0 > ?Hi?

3. H0 is in the same direction as Hi

4. H0 and Hi are in opposite directions

Select the correct answer using the codes given below:

Codes:

(A) 1 and 3

(B) 1 and 4

(C) 2 and 3 (Ans)

(D) 2 and 4

18. Silicon contains 5*1028 atoms per cubic meter. If it is doped with two parts per million of arsenic , then the electron density at room temperature will be approximately.

(A) 4*1023 m3

(B) 1023 m-3 (Ans)

(C) 2*106 m-3

(D) 104 m-3

19. In a certain temperature range, the electrical conductivity of a semi-conductor increases with increase in temperature. This is because

(A) both carrier concentration and mobilty of carriers increase with increasing temperature

(B) both carrier concentration and mobility of carriers decrease with increasing temperatures

(C) the carrier concentration increase substantially, but the mobility of carriers decreases with increase in temperature (Ans)

(D) the carrier concentration remains constant but the mobility of carriers increases in temperature

20. The Hall-effect voltage in intrinsic silicon

(A) is positive

(B) is zero

(C) is negative (Ans)

(D) changes sign on application of magnetic field

21. The function of oxide layer in IC fabricaton is

2. to insulate surface electricity

3. to produce chemical stable surface

4. to increase the metling point

Consider above statement then correct are :

(A) 1, 2 and 3 (Ans)

(B) 2, 3 and 4

(C) 3, 4 and 1

(D) 3 and 4 only

22. Consider a single crystal of an intrinsic semi-conductor. The number of free carriers at the fermi level at room temperature is

(A) half the total number of electrons in the crystal

(B) half the number of free electrons in the crystal (Ans)

(C) half the number of atoms in the crystal

(D) zero

23. If the molecular structure and density of the material are known, then which of the following material parameters may be determined from the er versus 1/T plot?

(A) Sum of electronic and ionic polarizabilities (Ans)

(B) Lattice constant

(C) Breakdown voltage

(D) Loss constant

24 The electron relaxation time of metal A is 2.7*10-4 sec that of B is 1.35*10-4 sec. The ratio of resistivity of B to resistivity of A will be

(A) 4.0

(B) 2.0 (Ans)

(C) 0.5

(D) 0.25

25. Electrical conductivity of copper reduces with addition of a small amount of nickel because

(A) the mobility decreases due to creation of new scattering centres for electrons (Ans)

(B) nickel is ferromagnetic

(C) less free electrons are available for conduction

(D) the electrons of copper become bound to nickel atoms and are not free to move

26. Magnetic susceptibility of an ideal Type-I super-conductor in the super-conductivity state is

(A) -8

(B) -1 (Ans)

(C) between 0 and -1

(D) zero

27. When the transition occurs to the super conducting state, the magnetic flux is excluded from the material. This is known as

(A) Magnetophobic effect

(B) Silsbee effect

(C) Meissner effect (Ans)

(D) Copper effect

28. Cu2 MnAl is

(A) piezoelectric

(B) paramagnetic

(C) ferrimagnetic

(D) ferromagnetic (Ans)

29. In an intrinsic semi-conductor, the mobility of electrons in the conduction band is

(A) zero

(B) less than the mobility of holes in the valence band

(C) equal to the mobility of holes in the valence band

(D) greater than the mobility of holes in the valence band (Ans)

30. The effect of doping intrinsic semi- conductors is to

(A) move the fermi level away from the centre of the forbidden band (Ans)

(B) move the fermi level towards the centre of the forbidden band

(C) change the crystal structure of the semi-conductor

(D) keep the fermi level at the middele of the forbidden band

31. The hall co-efficient of sample (A) of a semi-conductor is measured at room temperature. The hall co-efficient of A at room temperature is 4*10-4 m3 colomb-1 . The carrier concentration in sample A at room temperature is

(A) ~ 10-4 m-3

(B) ~ 1024 m-3

(C) ~ 104 m-3

(D) ~ 1022 m-3 (Ans)

32. The hall angle ? of a metal sample is

(A) independent of the magnetic flux density B

(B) independent of the carrier mobility

(C) independent of the density of free carriers

(D) dependent on magnetic flux density, carrier mobility and density of free carriers (Ans)

33. The resistance of a thermistor is 5000 O at 200 C and its resistance temperature co-efficient is 0.04/0C. A measurement with a lead resistance of 10 O will cause an error of

(A) 0.050 C (Ans)

(B) 0.10 C

(C) 0.40 C

(D) 0.80 C

34. When a solid crystal of sodium is formed, the 3s-band will have

(A) half as many states as the number of atoms (Ans)

(B) same number of states as there are atoms

(C) twice as many states as there are atoms

(D) no states at all

35. The relaxation time (t) in a perfect dielectric is

(A) 0 (Ans)

(B) 1

(C) 1 < t 8

(D) 8

36. The number of stress co-efficients or constants which characterize a piezoelectric material is

(A) 24 (Ans)

(B) 18

(C) 9

(D) 3

37. Which of the following pair (s) is/are correctly matched?

Material Application

1. Rochelle salt Phonograph

2. Barium titanate Amplifier

3. Quartz Oscillator

Select the correct answer using the codes given below :

(A) only 2

(B) 1 and 2

(C) 1 and 3 (Ans)

(D) 2 and 3

38. The conductivity of a metal at ultraviolet frequency (1014 Hz) approximately equals

(A) infinity

(B) zero

(C) d.c. conductivity

(D) half of d.c. conductivity (Ans)

39. Constantan is an alloy composed of

(A) 86% copper, 12% manganese and 2% nickel

(B) 76% nickel, 21% chromium, 2% manganese and 1% iron

(C) 60% copper and 40% nickel (Ans)

(D) 40% copper and 40% nickel and 20% carbon

40. Some of the characterizing parameters of a material are

1. Magnetic permeability

2. Electron relaxation time

3. Electron effective mass

4. Energy band gap

In case of metals, increase in one of the above parameters decreases its conductivity, while increase in another increase the conductivity. These two parameters are respectively.

(A) 1 and 3

(B) 3 and 2 (Ans)

(C) 4 and 3

(D) 1 and 2

41. What type of magnetic behaviour is observed in a type-I super-conductor?

(A) Perfect diamagnetism (Ans)

(B) Perfect paramagnetism

(C) Perfect ferromagnetism

(D) Perfect ferrimagnetism

42. The super-conducting transition temperature of lead is 7.26 K. If the initial field at OK is 64*103 Amp/m, then the critical field at 5 K is

(A) 0.3364*103 Amp/m

(B) 3.364*103 Amp/m

(C) 33.640*103 Amp/m (Ans)

(D) 336.400*103 Amp/m

43. Match List-I with List-II and select the correct answer using the codes given below the lists :

List-I List-II
(Material) (Classification)

(a) Mgo Fe2O3 1. Piezoelectric material

(b) BaTiO3 2. Ferrimagnetic material

(c) Cobalt 3. Ferromagnetic material

(d) Copper 4. Diamagnetic material

Codes :

(a) (b) (c) (d)

(A) 2 3 4 1

(B) 2 1 3 4

(C) 1 2 4 3

(D) 1 2 3 4

(Ans-B)

44. A paramagnetic material is used in an energy conversion process in which the following events occur:

1. Thermal energy is generated

2. Dipoles are turned

3. Magnetic field is generated

4. Material reacts to oppose it.

The correct sequence of these event is

(A) 3, 4, 2, 1

(B) 1, 4, 2, 3

(C) 1, 2, 4, 3

(D) 3, 2, 4, 1 (Ans)

45. A sample of iron carrying a current is subjected to a magnetic field. Match List-I with List-II to indicate the influence of angle between the magnetic field and current on the resistivity of the sample and select the correct answer using the codes given below the lists:

List-I List-II
(Direction of current) (Electrical resistivity)

(A) Parallel to magnetisation 1. Increase

(B) Perpendicular magnetisation 2. Decrease

3. Unchanged

Codes :

(a) (b)

(A) 1 2

(B) 2 1

(C) 2 3

(D) 3 1

(Ans-D)

46. Some magnetic materials may be classified on the basis of

1. Susceptibility

2. Saturation

3. Spin arrangement

4. Nature of hysteresis loop

5. Domain structure

6. Critical temperature above which it behaves as a paramagnetic material.

Out of these, those which can be used to distinguish between ferri and ferromagnetic matgerials would include

(A) 1, 3 and 4 (Ans)

(B) 2, 3 and 6

(C) 3, 4 and 5

(D) 3, 5 and 6

47. Assuming carrier mobility to be temperature independent, it can be shown that pure Si (Eg = 1.1 eV) and Ge (Eg = 0.7 eV) have the same conductivity at a temperature of

(A) 191 K

(B) 300 K

(C) 471 K

(D) 1470 K (Ans)

48. The processes that can be used to make the steel magnetically softer are

1. Annealing

2. Grain growth

3. Decarburization

4. Quenching

(A) 1, 2 and 3 (Ans)

(B) 2, 3 and 4

(C) 2 and 3 only

(D) 3 and 4 only

49. Polarization is a measure of

(A) dielectric constant per unit volume (Ans)

(B) voltage gradient of produce eslectrical breakdown

(C) product of charge and distance

(D) excess charge density

50 Consider the following semi-conductor diodes

1. Germanium diode

2. Silicon diode

3. Tunnel diode

4. Schottky diode

The correct increasing order of forward voltage drop of these diodes is

(A) 1,3,2,4

(B) 1,2,3,4

(C) 3,4,2,1

(D) 3,1,4,2 (Ans)

BSNL Electronics-Communication-Engineering-previous-questions
BSNL previous years objective type solved question papers of Electronics, Electrical, Engineering Mechanics placement papers

1. To neglect a voltage source, the terminals across the source are

(A) open circuited

(B) short circuited (Ans)

(C) replaced by some resistance

(D) replaced by an inductor

2. Which is a digital communication system ?

(A) FM

(B) AM

(C) PCM (Ans)

(D) PAM

3. In a resonant circuit, the power factor at resonance is

(A) zero

(B) unity (Ans)

(C) 0.5

(D) 1.5

4. In TV systems the frame frequency is

(A) 100

(B) 60

(C) 50

(D) 25 (Ans)

5. The function 3 s has
(s + 1) (s + 2)

(A) one zero, two poles (Ans)

(B) no zero, one pole

(C) no zero, two poles

(D) one zero, no pole

Solution : G (s) = 3s has one zero at s = 0 and two poles at s = – 1, – 2.
(s + 1) (s + 2)

6. One electron volt is equivalent to

(A) 1.6 * 10-10 J

(B) 1.6 * 10-13 J

(C) 1.6 * 10-16 J

(D) 1.6 * 10-19 J (Ans)

7. Which of the following is donor impurity element ?

(A) Aluminium

(B) Boron

(C) Phosphorous (Ans)

(D) Indium.

8. The diameter of an atom is of the order

(A) 10-6 m

(B) 10-10 m (Ans)

(C) 10-15 m

(D) 10-21 m

9. A transistor is basically an amplifying device for

(A) power

(B) voltage

(C) current (Ans)

(D) all of these

10. If the d.c. valve of a rectified output is 300 V and peak to peak ripple voltage is 10 V, the ripple factor is

(A) 1.18%

(B) 3.33% (Ans)

(C) 3.36%

(D) 6.66%

Solution : rms value of output

= ?3002 + 102 = 300.166 V

Average value = 300 V

Form factor RMS value = 300.166 = 1.00055.
Average value 300

Ripple factor = ?(Form factor)2 – 1

= ?(1.0005)2 – 1 = 0.0333

= 3.33%.

11. Full wave rectifier output has ripple factor of

(A) 1.11 (Ans)

(B) 1.21

(C) 1.41

(D) 1.51

12. In a common base connection IE = 2 mA, IC = 1.9 mA. The value of base current is

(A) 0.1 m (Ans)

(B) 0.2 mA

(C) 0.3 mA

(D) zero

Solution : IE = 2 mA IC = 1.9 mA

Ib = IE – IC = (2 – 1.9) = 0.1 mA.

13. For the action of transistor the base region must be

(A) P-type material

(B) N-type material

(C) very narrow (Ans)

(D) highly doped

14. Compared to a CB amplifier the CE amplifier has higher

(A) current amplification

(B) output dynamic resistance

(C) leakage current

(D) input dynamic resistance

(E) all of the above (Ans)

15. When a transistor is biased to cut-off its Y is

(A) 0.5

(B) 0

(C) 1.0 (Ans)

(D) 0.8

16. An ideal voltage amplifier should have

(A) Ri = 0, R0 = 0

(B) Ri = 0, R0 = ¥

(C) Ri = ¥, R0 = 0 (Ans)

(D) Ri = 0, R0 = ¥

17. Barichausen criterion for sustained oscillator is

(A) A? = 1 Ð00 (Ans)

(B) A? = 0

(C) A? = 1 Ð1800

(D) A = 1/??

18. The value of plastic capacitance for a triode may range from

(A) 2 ?F to 12 ?F

(B) 20 ?F to 120 ?F

(C) 2 pF to 12 pF (Ans)

(D) 20 pF to 120 pF

19. A colpitts oscillator uses

(A) tapped coil

(B) inductive feedback

(C) tapped capacitance (Ans)

(D) no tuned LC circuit

20. A typical frequency for a RC feedback oscillator is

(A) 1 KHz (Ans)

(B) 100 MHz

(C) 1000 MHz

(D) 1 GHz

BSNL Mechanical Engineering Questions with answer
BSNL mechanical engineering questions for all examinsions,BSNL JTO DGM znd other exams in 2013 model questions for practice

1. An Aeroplane travels at 400 km/hr at sea level where the temperature is 15oC. The velocity of the Aeroplane at the same Mach number at an altitude where a temperature of -25Cis prevailing, would be
a) 126.78 km/hr
b) 130.6 km/hr
c) 371.2 km/hr
d) 400.10 km/hr (Ans)

2. The plot for the pressure ratio along the length of the convergent-divergent nozzle is shown in the given figure. The sequence of the flow conditions labelled 1,2,3, and 4 in the figure is respectively

a) supersonic, sonic, subsonic and supersonic
b) sonic, supersonic, subsonic and supersonic
c) subsonic, supersonic, sonic and subsonic
d) subsonic, sonic, supersonic and subsonic (Ans)

3. If the full -scale turbine is required to work under a head of 30 m and to run at 428 r.p.m., then a quarter-scale turbine model tested under a head of 10 m must run at
a) 143 r.p.m.
b) 341 r.p.m.
c) 428 r.p.m.
d) 988 r.p.m. (Ans)

4. The dimensionless group formed by wavelength ?, density of fluid ?, acceleration due to gravity g and surface tension s, is
a) s (Ans)
?2g?
b) s
?g2?
c) sg
?2?
d) ?
?2g?

5. Which one of the following sets of standard flows is uperimposed to represent the flow around a rotating cylinder ?
a) Doublet, vortex and uniform flow (Ans)
b) Source, vortex and uniform flow
c) Sink, vortex and uniform flow
d) Vortex and uniform flow

6.
A float of cubical shape has sides of 10 cm. The float valve just touches the valve seat to have a flow area of 0.5 cm2 as shown in the given figure. If the pressure of water in the pipeline is 1 bar, the rise of water level h in the tank to just stop the water flow will be
a) 7.5 cm
b) 5.0 cm (Ans)
c) 2.5 cm
d) 0.5 cm

7. A U-tube manometer is connected to a pipeline conveying water as shown in the given figure. The pressure head of water in the pipeline is

a) 7.12 m
b) 6.56 m
c) 6.0 m (Ans)
d) 5.12

8. The eye of a tornado has a radium of 40 m. If the maximum wind velocity is 50 m/s, the velocity at a distance of 80 m radius is
a) 100 m/s
b) 2500 m/s
c) 31.25 m/s
d) 25 m/s (Ans)

9. If a vessel containing liquid moves downward with constant acceleration d, then
a) the pressure throughout the liquid mass is atmosphere
b) the pressure in the liquid mass is greater than the hydrostatic pressure
c) there will be vacuum in the liquid
d) the pressure throughout the liquid mass is greater than atmosphere (Ans)

10. Improve streamlining produces 25% reduction in the drag coefficient of a torpedo. When it is travelling fully submerged and assuming the driving power to remain the same, the increase in speed will be
a) 10 % (Ans)
b) 20 %
c) 25 %
d) 30 %

11. If a bullet is fired in standard air at 15oC at the Mach angle of 30oC, the velocity of the bullets would be
a) 513.5 m/s
b) 585.5 m/s
c) 645.5 m/s
d) 680.5 m/s (Ans)

12. A stream function is given by (x2-y2). The potential function of the flow will be
a) 2xy + f(x)
b) 2xy + constant (Ans)
c) 2(x2-y2)
d) 2xy + f(y)

13. The height of a cylindrical container is twice that of its diameter. The ratio of the horizontal forces on the wall of the cylinder when it is completely filled to that when it is half filled with the same liquid is
a) 2 (Ans)
b) 3
c) 3.5
d) 4

14. The velocities and corresponding flow areas of the branches labelled 1,2,3,4 and 5 for a pipe system shown in the given figure are given in the following table :

Pipe Label l Velocity Area 1 5 cm/s 4 sq cm 2 6 cm/s 5 sq cm 3 V3 cm/s 2 sq cm 4 4 cm/s 10 sq cm 5 V5 cm/s 8 sq cm
a) 2.5 cm/s
b) 5 cm/s (Ans)
c) 7.5 cm/s
d) 10 cm/s

15. A pipe is connected in series to another pipe diameter is twice and length is 32 times that of the first pipe. The ratio of frictional head losses for the first pipe to those for the second pipe is (both the pipes have the same frictional constant)
a) 8
b) 4
c) 2
d) 1 (Ans)

16. Which one of the following statements is correct ?
a) Hydraulic grade line and energy grade line are the same in fluid flow problems
b) Energy grade line lies above the hydraulic grade line and is always parallel to it
c) Energy grade line lies above the hydraulic grade line and they are separated from each other by a vertical distance equal to the velocity head (Ans)
d) The hydraulic grade line slopes upwards meeting the energy grade line only at the exit of flow

17. If laminar flow takes place in two pipes, having relative roughnesses of 0.002 and 0.003, at a Reynolds number of 1815, then
a) the pipe of relative roughness of 0.003 has a higher friction factor (Ans)
b) the pipe of relative roughness of 0.003 has a lower friction factor
c) both pipes have the same friction factor
d) no comparison is possible due to inadequate data

18. A pipeline connecting two reservoirs has its diameter reduced by 20% due to deposition of Chemicals. For a given head difference in the reservoirs with unaltered friction factor, this would cause a reduction in discharge of
a) 42.8% (Ans)
b) 20%
c) 17.8%
d) 10.6%

19. A tank containing water has two orifices of the same size at depths of 40 cm and 90 cm below the free surface of water. The ratio of discharges through these orifices is
a) 1:1
b) 2:3 (Ans)
c) 4:9
d) 16:81

20. A Pilot static tube is used to measure the velocity of water using a differential gauge which contains a manometric fluid of relative density 1.4. The deflection of the gauge fluid when water flows at a velocity of 1.2 m/s will be (the coefficient of the tube may be assumed to be 1)
a) 183.5 mm
b) 52.4 mm (Ans)
c) 5.24 mm
d) 73.4 mm

21. The development of boundary layer zones labelled P,Q, R and S over a flat plate is shown in the given figure

Based on this figure, match List (Boundary layer zones) with List II (Types of boundary layer) and select the correct answer using the codes given below the Lists :
List -I List -II
a) P 1. Transitional
b) Q 2. Laminar viscous sub-layer
c) R 3. Laminar
d) S 4. Turbulent
Codes :
A B C D
a) 3 1 2 4 (Ans)
b) 3 2 1 4
c) 4 2 1 3
d) 4 1 2 3

22. A pipe of 20 cm diameter and 30 km length transports oil from a tanker to the shore with a velocity of 0.318 m/s. The flow is laminar. If µ = 0.1 N-m/s2, the power required for the flow would be
a) 9.25 kW (Ans)
b) 8.36 kW
c) 7.63 kW
d) 10.13 kW

23. In a turbulent boundary layer over the entire length of a plate, the boundary layer thickness increases with its distance X from the leading edge as
a) X 1/2
b) X1/5
c) X2/5
d) X4/5 (Ans)

24. Separation of fluid flow is caused by
a) reduction of pressure in the direction of flow
b) reduction of the boundary layer thickness
d) presence of favourable pressure gradient

25. When pressure drag over a body is large as compared to the friction drag, then the shape of the body is that of
a) an aerofoil
b) a streamlined body
c) a two-dimensional body
d) a bluff body (Ans)

26. A circular cylinder of 400 mm diameter is rotated about its axis in a stream of water having a uniform velocity of 4 m/s. When both the stagnation points coincide, the lift force experienced by the cylinder is
a) 160 kN/m
b) 10.05 kN/m (Ans)
c) 80 kN/m
d) 40.2 kN/m

27. An automobile moving at a velocity of 40km/hr is experiencing a wind resistance of 2kN. If the automobile is moving at a velocity of 50km/hr, the power required to overcome the wind resistance is
a) 43.4kW (Ans)
b) 3.125 kW
c) 2.5 kW
d) 27.776 kW

28. When a cylinder is placed in an ideal fluid and the flow is uniform, the pressure coefficient Cp is equal to
a) 1-sin2? (Ans)
b) 1- 2 sin2?
c) 1- 4 sin2?
d) 1- 8 sin2?

29. If the upstream Mach number of a normal shock occuring in air (k=1.4) is 1.68, then the Mach number after the shock is
a) 0.84
b) 0.646 (Ans)
c) 0.336
d) 0.564

30. Which one of the following sets of thermodynamic laws/ relations is directly involved in determining the final properties during an adiabatic mixing process?
a) The first and second laws of thermodynamics
b) The second law of thermodynamics and steady flow relations
c) Perfect gas relationship and steady flow relations
d) The first law of thermodynamics and perfect gas relationship (Ans)

31. The air wiht enthalpy of 100 kJ/kg is compressed by an air compressor to a pressure and temperature at which its enthalpy becomes 200 kJ/kg. The loss of heat is 40kJ/kg from the compressor as the air passes through it. Neglecting kinetic and potential energies, the power required for an air mass flow of 0.5 kg/s is
a) 30kW (Ans)
b) 50kW
c) 70kW
d) 90kW

32. Consider the following statements :
i) The first law of thermodynamics is a law of conservation of energy
ii) Perpetual motion machine of the first kind converts energy into euivalent work
iii) A closed system does not exchange work or energy with its surroundings
iv) The second law of thermodynamic stipulates the law of conservation of energy and entropy. Which of the statements are correct ?
a) (i) and (iii)
b) (ii) and (iv)
c) (ii), (iii) and (iv)
d) (i), (ii) and (iii) (Ans)

33. A heat engine receives 1000 kW of heat at a constant temperature of 285 oC and rejects 492 kW of heat at 5oC. Consider the following thermodynamic cycles in this regard:
(i) Carnot cycle
(ii) Reversible cycle
(iii) Irreversible cycle
Which of these cycles could possible be executed by the engine ?
a) 1 alone (Ans)
b) 3 alone
c) 1 and 2
d) None 1, 2 and 3

34. The process 1-2 for steam shown in the given figure is

a) isobaric
b) isentropic
c) isenthalpic (Ans)
d) isothermal

35. In which one of the following working substances, does the relation T2 = (P2)0.286 hold good if the process takes place with zero heat transfer ?
T1 P1
a) West steam
b) Superheated steam (Ans)
c) Petrol vapour and air mixture
d) Air

36. Consider the following statements :
When dry saturated steam is throttled from a higher pressure to a lower pressure, the
a) pressure decreases and the volume increases (Ans)
b) temperature decreases and the steam becomes superheated
c) temperature and the dryness fraction increase
d) entropy increases without any change in enthalpy

37. In which one of the following situations the entropy change will be negative
a) Air expands istothermally from 6 bars to 3 bars (Ans)
b) Air is compressed to half the volume at constant pressure
c) Hear is supplied to air at constant volume till the pressure becomes three folds
d) air expands isentropically from 6 bars to 3 bars

38. The heat added to a closed system during a reversible process is given by Q = aT + ßT2, where a and ß are constants. The entropy change of the system as its temperature changes from T1 to T2 is equal to

39. The internal energy of a gas obeying van der Waals equation (p + a/V2) (v-b) = RT depends on its
a) temperature
b) temperature and pressure (Ans)
c) temperature and specific volume
d) pressure and specific volume

40. Consider the following statements :
A real gas obeys perfect gas law at very
(i) high temperature
(ii) high pressure
(iii) low pressures
Which of these statements is/are correct ?
a) (i) alone
b) (i) and (iii)
c) (ii) alone
d) (iii) alone (Ans)

41. The capacity of an air compressor is specified as 10 m3/min. It means that the compressor is capable of
a) supplying 3 m3 of compressed air per minute (Ans)
b) compressing 3 m3 of free air per minute
c) supplying 3 m3 of compressed air at NTP
d) compressing 3 m3 of standard air per minute

42. A two-stage compressor takes in air at 1.1 bars and discharges at 20 bars. For maximum efficiency, the intermediate pressure is
a) 10.55 bars
b) 7.33 bars
c) 5.5 bars
d) 4.7 bars (Ans)

43. For the same maximum pressure and heat input, the most efficient cycle is
a) Otto cycle (Ans)
b) Diesel cycle
c) Brayton cycle
d) Dual combustion cycle

44. In a petrol engine car, which one of the following performance characteristics is affected by the front-end volatility of the gasoline used ?
a) Hot starting and vapour lock
b) Engine warm -up and spark plug fouling
c) Spark plug fouling and hot starting
d) Vapour lock, engine warm -up and spark plug fouling (Ans)

45. In turbo prop, the expansion of gases takes place approximately
a) 100% in the turbine (Ans)
b) 80% in the turbine and 20% in the nozzle
c) 50% in the turbine and 50% in the nozzle
d) 100% in the nozzle

46. The most commonly used moderator in Nuclear power plants is
a) heavy water
b) concrete and bricks
c) steel
d) graphite (Ans)

47. Shielding in a nuclear reactor is generally done to protect against
a) excess electrons
b) X-rays
c) a and ß rays
d) neutron and gamma rays (Ans)

48. Partial admission steam turbine refers to the situation where the
c) nozzles do not occupy the complete circumference leading into the annulus

49. In a steam power plant, the ratio of the isentropic heat drop in the prime mover to the amount of heat supplied per unit mass of steam is known as
a) stage efficiency
b) degree of reaction
c) Rankine efficiency (Ans)
d) relative efficiency

50. Reciprocating compressors are provided with
a) simple disc/plate valve (Ans)
b) poppet valve
d) solenoid valve

51. The gross head available to hydraulic power plant is 100m. The utilised head in the runner of the hydraulic turbine is 72 m. If the hydraulic efficiency of the turbine is 90% , the pipe friction head is estimated to be
a) 20 m (Ans)
b) 18 m
c) 16.2 m
d) 1.8 m

52. Which one of the following pairs of formulae represents the specific speeds of turbine and pump respectively ? (Notations have their usual meanings)
a) NQ 1/2 and NP1/2
H3/4 H5/4
b) NQ 1/2 and NP1/2
H3/4 H3/4
c) NP1/2 and NQ1/2
H3/4 H5/4
d) NP 1/2 and NQ1/2 (Ans)
H5/4 H3/4

53. The outer surface of a long cylinder is maintained at constant temperature. The cylinder does not have any heat source
The temperature in the cylinder will
c) be independent of radius (Ans)

54. A composite plane wall is made up of two different materials of the same thickness and having a thermal conductivities of k1 and k2 respectively. The equivalent thermal conductivity of the slab is
a) k1+k2

b) k1k2

c) k1+k2 (Ans)
k1k2

d) 2k1k2
k1+k2

55. A copper wire of radius 0.5 mm is insulated with a sheathing of thickness 1 mm having a thermal conductivity of 0.5 W/m-K. The outside convective heat transfer coefficient is 10W/m2-K. If the thickness of insulation sheathing is raised by 10 mm, then the electrical current-carrying capacity of the wire will
a) increase
b) decrease
c) remain the same (Ans)
d) vary depending upon the electrical conductivity of the wire

56. For the fully developed laminar flow and heat transfer in a uniformly heated long circular tube, if the flow velocity is doubled and the tube diameter is halved, the heat transfer coefficient will be
a) double of the original value
b) half of the original value (Ans)
c) same as before
d) four times of the original value

57. Heat transfer by radiation between two grey bodies of emissivity e is proportional to (notations have their usual meanings)
a) (Eb – J)
(I – e)
b) (Eb – J) (Ans)
(I – e) /e
c) (Eb – J)
(I – e)2
d) (Eb – J)
(I – e2)

58. The Nusselt number is related to Reynolds number in laminar and turbulent flows respectively as
a) Re-1/2 and Re0.8
b) Re1/2 and Re0.8 (Ans)
c) Re-1/2 and Re-0.8
d) Re1/2 and Re-0.8

59. In respect of free convection over a vertical flat plate the Nusselt number varies with Grashof number ‘Gr’ as
a) Gr and Gr1/2 for laminar and turbulent flows respectively (Ans)
b) Gr 1/2 and Gr1/3 for laminar and turbulent flows respectively
c) Gr1/4 and Gr1/3 for laminar and turbulent flows respectively
d) Gr1/3 and Gr1/4 for laminar and turbulent flows respectively

60. The enthalpies at the beginning of compression, at the end of compression and at the end of condensation are respectively 185 kJ/kg and 85 kJ/kg. The COP of the vapour compression refrigeration system is
a) 0.25
b) 5.4
c) 4 (Ans)
d) 1.35

61. The COP of a heat pump ßHP and the COP of a refrigerator ßRef are related as
a) ßHP + ßRef
b) ßHP – ßRef = 1 (Ans)
c) ßRef – ßHP = 1
d) ßHP – ßRef = 0

62. The discharge pressure of the compressor in the refrigeration system goes up due to the
a) lower volumetric efficiency of the compressor
b) formation of scale in the condenser (Ans)
c) large size of the condenser
d) undercharge of the refrigerant

63. The leakage in a Freon-based refrigeration system can be detected by using a/an
a) oxy-acetylene torch
b) halide torch (Ans)
c) sulphur torch
d) blue litmus paper

64. When warm saturated air is cooled
a) excess moisture condenses (Ans)
b) excess moisture condenses but relative humidity remains unchanged
c) excess moisture condenses and specific humidity increases but relative humidity remains unchanged.
d) specific humidity increases and relative humidity decreases
65. When dry-bulb and wet-bulb temperature are identical, it means that the
a) air is fully saturated and dew-point temperature has reached
b) air is fully saturated (Ans)
c) dew-point temperature has reached and humidity is 100%
d) partial pressure of water vapour is equal to total pressure

66. The desirable air velocity in the occupied zone for comfort for summer air-conditioners is in the range of
a) 6-7 m/minute
b) 4-5m/minute
c) 2-3 m/minute
d) 0.5-1.5 m/minute (Ans)

67. An air-conditioned room of volume 10 cm3 has infiltration of air equivalent to 3 air changes. Density of air is 1.2 kg/3, specific heat Cp is 1 kJ/kg-K and temperature difference between room and ambient air is 20K. The sensible heat load due to infiltrated air is
a) 60 kJ/hr
b) 12 kJ/hr
c) 6 kW
d) 0.2 k W (Ans)

68. If heat and mass transfer take place simultaneously, the ratio of heat transfer coefficient to the mass transfer coefficient is a function of the ratio of
a) Schmidt and Reynolds numbers (Ans)
b) Schmidit and Prandtl numbers
c) Nusselt and Lewis number
d) Reynolds and Lewis numbers

69. Consider the following statements :
The typical air velocities in the ducts of air-conditioning systems are
(i) lower in residential buildings as compared to those of public buildings
(ii) higher in residential buildings as compared to those of public buildings
(iii) higher in industrial buildings as compared to those of public buildings
(iv) equal in all types of buildings
Which of these statements is/are correct ?
a) (i) alone
b) (i) and (iii) (Ans)
c) (ii) and (iii)
d) (iv) alone

70. Consider the following parameters :
(i) Dry-bulb temperature
(ii) Humidity ratio
(iii) Air velocity
Which of these parameters are taken into account for determining effective temperature for human comfort ?
a) (i) and (ii)
b) (i) and (iv)
c) (ii), (iii) and (iv)
d) (i), (ii) and (iii) (Ans)

BSNL mechanical engineering questions for all examinsions,BSNL JTO DGM znd other exams in 2013 model questions for practice

1. An Aeroplane travels at 400 km/hr at sea level where the temperature is 15oC. The velocity of the Aeroplane at the same Mach number at an altitude where a temperature of -25Cis prevailing, would be
a) 126.78 km/hr
b) 130.6 km/hr
c) 371.2 km/hr
d) 400.10 km/hr (Ans)

2. The plot for the pressure ratio along the length of the convergent-divergent nozzle is shown in the given figure. The sequence of the flow conditions labelled 1,2,3, and 4 in the figure is respectively

a) supersonic, sonic, subsonic and supersonic
b) sonic, supersonic, subsonic and supersonic
c) subsonic, supersonic, sonic and subsonic
d) subsonic, sonic, supersonic and subsonic (Ans)

3. If the full -scale turbine is required to work under a head of 30 m and to run at 428 r.p.m., then a quarter-scale turbine model tested under a head of 10 m must run at
a) 143 r.p.m.
b) 341 r.p.m.
c) 428 r.p.m.
d) 988 r.p.m. (Ans)

4. The dimensionless group formed by wavelength ?, density of fluid ?, acceleration due to gravity g and surface tension s, is
a) s (Ans)
?2g?
b) s
?g2?
c) sg
?2?
d) ?
?2g?

5. Which one of the following sets of standard flows is uperimposed to represent the flow around a rotating cylinder ?
a) Doublet, vortex and uniform flow (Ans)
b) Source, vortex and uniform flow
c) Sink, vortex and uniform flow
d) Vortex and uniform flow

6.
A float of cubical shape has sides of 10 cm. The float valve just touches the valve seat to have a flow area of 0.5 cm2 as shown in the given figure. If the pressure of water in the pipeline is 1 bar, the rise of water level h in the tank to just stop the water flow will be
a) 7.5 cm
b) 5.0 cm (Ans)
c) 2.5 cm
d) 0.5 cm

7. A U-tube manometer is connected to a pipeline conveying water as shown in the given figure. The pressure head of water in the pipeline is

a) 7.12 m
b) 6.56 m
c) 6.0 m (Ans)
d) 5.12

8. The eye of a tornado has a radium of 40 m. If the maximum wind velocity is 50 m/s, the velocity at a distance of 80 m radius is
a) 100 m/s
b) 2500 m/s
c) 31.25 m/s
d) 25 m/s (Ans)

9. If a vessel containing liquid moves downward with constant acceleration d, then
a) the pressure throughout the liquid mass is atmosphere
b) the pressure in the liquid mass is greater than the hydrostatic pressure
c) there will be vacuum in the liquid
d) the pressure throughout the liquid mass is greater than atmosphere (Ans)

10. Improve streamlining produces 25% reduction in the drag coefficient of a torpedo. When it is travelling fully submerged and assuming the driving power to remain the same, the increase in speed will be
a) 10 % (Ans)
b) 20 %
c) 25 %
d) 30 %

11. If a bullet is fired in standard air at 15oC at the Mach angle of 30oC, the velocity of the bullets would be
a) 513.5 m/s
b) 585.5 m/s
c) 645.5 m/s
d) 680.5 m/s (Ans)

12. A stream function is given by (x2-y2). The potential function of the flow will be
a) 2xy + f(x)
b) 2xy + constant (Ans)
c) 2(x2-y2)
d) 2xy + f(y)

13. The height of a cylindrical container is twice that of its diameter. The ratio of the horizontal forces on the wall of the cylinder when it is completely filled to that when it is half filled with the same liquid is
a) 2 (Ans)
b) 3
c) 3.5
d) 4

14. The velocities and corresponding flow areas of the branches labelled 1,2,3,4 and 5 for a pipe system shown in the given figure are given in the following table :

Pipe Label l Velocity Area 1 5 cm/s 4 sq cm 2 6 cm/s 5 sq cm 3 V3 cm/s 2 sq cm 4 4 cm/s 10 sq cm 5 V5 cm/s 8 sq cm
a) 2.5 cm/s
b) 5 cm/s (Ans)
c) 7.5 cm/s
d) 10 cm/s

15. A pipe is connected in series to another pipe diameter is twice and length is 32 times that of the first pipe. The ratio of frictional head losses for the first pipe to those for the second pipe is (both the pipes have the same frictional constant)
a) 8
b) 4
c) 2
d) 1 (Ans)

16. Which one of the following statements is correct ?
a) Hydraulic grade line and energy grade line are the same in fluid flow problems
b) Energy grade line lies above the hydraulic grade line and is always parallel to it
c) Energy grade line lies above the hydraulic grade line and they are separated from each other by a vertical distance equal to the velocity head (Ans)
d) The hydraulic grade line slopes upwards meeting the energy grade line only at the exit of flow

17. If laminar flow takes place in two pipes, having relative roughnesses of 0.002 and 0.003, at a Reynolds number of 1815, then
a) the pipe of relative roughness of 0.003 has a higher friction factor (Ans)
b) the pipe of relative roughness of 0.003 has a lower friction factor
c) both pipes have the same friction factor
d) no comparison is possible due to inadequate data

18. A pipeline connecting two reservoirs has its diameter reduced by 20% due to deposition of Chemicals. For a given head difference in the reservoirs with unaltered friction factor, this would cause a reduction in discharge of
a) 42.8% (Ans)
b) 20%
c) 17.8%
d) 10.6%

19. A tank containing water has two orifices of the same size at depths of 40 cm and 90 cm below the free surface of water. The ratio of discharges through these orifices is
a) 1:1
b) 2:3 (Ans)
c) 4:9
d) 16:81

20. A Pilot static tube is used to measure the velocity of water using a differential gauge which contains a manometric fluid of relative density 1.4. The deflection of the gauge fluid when water flows at a velocity of 1.2 m/s will be (the coefficient of the tube may be assumed to be 1)
a) 183.5 mm
b) 52.4 mm (Ans)
c) 5.24 mm
d) 73.4 mm

21. The development of boundary layer zones labelled P,Q, R and S over a flat plate is shown in the given figure

Based on this figure, match List (Boundary layer zones) with List II (Types of boundary layer) and select the correct answer using the codes given below the Lists :
List -I List -II
a) P 1. Transitional
b) Q 2. Laminar viscous sub-layer
c) R 3. Laminar
d) S 4. Turbulent
Codes :
A B C D
a) 3 1 2 4 (Ans)
b) 3 2 1 4
c) 4 2 1 3
d) 4 1 2 3

22. A pipe of 20 cm diameter and 30 km length transports oil from a tanker to the shore with a velocity of 0.318 m/s. The flow is laminar. If µ = 0.1 N-m/s2, the power required for the flow would be
a) 9.25 kW (Ans)
b) 8.36 kW
c) 7.63 kW
d) 10.13 kW

23. In a turbulent boundary layer over the entire length of a plate, the boundary layer thickness increases with its distance X from the leading edge as
a) X 1/2
b) X1/5
c) X2/5
d) X4/5 (Ans)

24. Separation of fluid flow is caused by
a) reduction of pressure in the direction of flow
b) reduction of the boundary layer thickness
d) presence of favourable pressure gradient

25. When pressure drag over a body is large as compared to the friction drag, then the shape of the body is that of
a) an aerofoil
b) a streamlined body
c) a two-dimensional body
d) a bluff body (Ans)

26. A circular cylinder of 400 mm diameter is rotated about its axis in a stream of water having a uniform velocity of 4 m/s. When both the stagnation points coincide, the lift force experienced by the cylinder is
a) 160 kN/m
b) 10.05 kN/m (Ans)
c) 80 kN/m
d) 40.2 kN/m

27. An automobile moving at a velocity of 40km/hr is experiencing a wind resistance of 2kN. If the automobile is moving at a velocity of 50km/hr, the power required to overcome the wind resistance is
a) 43.4kW (Ans)
b) 3.125 kW
c) 2.5 kW
d) 27.776 kW

28. When a cylinder is placed in an ideal fluid and the flow is uniform, the pressure coefficient Cp is equal to
a) 1-sin2? (Ans)
b) 1- 2 sin2?
c) 1- 4 sin2?
d) 1- 8 sin2?

29. If the upstream Mach number of a normal shock occuring in air (k=1.4) is 1.68, then the Mach number after the shock is
a) 0.84
b) 0.646 (Ans)
c) 0.336
d) 0.564

30. Which one of the following sets of thermodynamic laws/ relations is directly involved in determining the final properties during an adiabatic mixing process?
a) The first and second laws of thermodynamics
b) The second law of thermodynamics and steady flow relations
c) Perfect gas relationship and steady flow relations
d) The first law of thermodynamics and perfect gas relationship (Ans)

31. The air wiht enthalpy of 100 kJ/kg is compressed by an air compressor to a pressure and temperature at which its enthalpy becomes 200 kJ/kg. The loss of heat is 40kJ/kg from the compressor as the air passes through it. Neglecting kinetic and potential energies, the power required for an air mass flow of 0.5 kg/s is
a) 30kW (Ans)
b) 50kW
c) 70kW
d) 90kW

32. Consider the following statements :
i) The first law of thermodynamics is a law of conservation of energy
ii) Perpetual motion machine of the first kind converts energy into euivalent work
iii) A closed system does not exchange work or energy with its surroundings
iv) The second law of thermodynamic stipulates the law of conservation of energy and entropy. Which of the statements are correct ?
a) (i) and (iii)
b) (ii) and (iv)
c) (ii), (iii) and (iv)
d) (i), (ii) and (iii) (Ans)

33. A heat engine receives 1000 kW of heat at a constant temperature of 285 oC and rejects 492 kW of heat at 5oC. Consider the following thermodynamic cycles in this regard:
(i) Carnot cycle
(ii) Reversible cycle
(iii) Irreversible cycle
Which of these cycles could possible be executed by the engine ?
a) 1 alone (Ans)
b) 3 alone
c) 1 and 2
d) None 1, 2 and 3

34. The process 1-2 for steam shown in the given figure is

a) isobaric
b) isentropic
c) isenthalpic (Ans)
d) isothermal

35. In which one of the following working substances, does the relation T2 = (P2)0.286 hold good if the process takes place with zero heat transfer ?
T1 P1
a) West steam
b) Superheated steam (Ans)
c) Petrol vapour and air mixture
d) Air

36. Consider the following statements :
When dry saturated steam is throttled from a higher pressure to a lower pressure, the
a) pressure decreases and the volume increases (Ans)
b) temperature decreases and the steam becomes superheated
c) temperature and the dryness fraction increase
d) entropy increases without any change in enthalpy

37. In which one of the following situations the entropy change will be negative
a) Air expands istothermally from 6 bars to 3 bars (Ans)
b) Air is compressed to half the volume at constant pressure
c) Hear is supplied to air at constant volume till the pressure becomes three folds
d) air expands isentropically from 6 bars to 3 bars

38. The heat added to a closed system during a reversible process is given by Q = aT + ßT2, where a and ß are constants. The entropy change of the system as its temperature changes from T1 to T2 is equal to

39. The internal energy of a gas obeying van der Waals equation (p + a/V2) (v-b) = RT depends on its
a) temperature
b) temperature and pressure (Ans)
c) temperature and specific volume
d) pressure and specific volume

40. Consider the following statements :
A real gas obeys perfect gas law at very
(i) high temperature
(ii) high pressure
(iii) low pressures
Which of these statements is/are correct ?
a) (i) alone
b) (i) and (iii)
c) (ii) alone
d) (iii) alone (Ans)

41. The capacity of an air compressor is specified as 10 m3/min. It means that the compressor is capable of
a) supplying 3 m3 of compressed air per minute (Ans)
b) compressing 3 m3 of free air per minute
c) supplying 3 m3 of compressed air at NTP
d) compressing 3 m3 of standard air per minute

42. A two-stage compressor takes in air at 1.1 bars and discharges at 20 bars. For maximum efficiency, the intermediate pressure is
a) 10.55 bars
b) 7.33 bars
c) 5.5 bars
d) 4.7 bars (Ans)

43. For the same maximum pressure and heat input, the most efficient cycle is
a) Otto cycle (Ans)
b) Diesel cycle
c) Brayton cycle
d) Dual combustion cycle

44. In a petrol engine car, which one of the following performance characteristics is affected by the front-end volatility of the gasoline used ?
a) Hot starting and vapour lock
b) Engine warm -up and spark plug fouling
c) Spark plug fouling and hot starting
d) Vapour lock, engine warm -up and spark plug fouling (Ans)

45. In turbo prop, the expansion of gases takes place approximately
a) 100% in the turbine (Ans)
b) 80% in the turbine and 20% in the nozzle
c) 50% in the turbine and 50% in the nozzle
d) 100% in the nozzle

46. The most commonly used moderator in Nuclear power plants is
a) heavy water
b) concrete and bricks
c) steel
d) graphite (Ans)

47. Shielding in a nuclear reactor is generally done to protect against
a) excess electrons
b) X-rays
c) a and ß rays
d) neutron and gamma rays (Ans)

48. Partial admission steam turbine refers to the situation where the
c) nozzles do not occupy the complete circumference leading into the annulus

49. In a steam power plant, the ratio of the isentropic heat drop in the prime mover to the amount of heat supplied per unit mass of steam is known as
a) stage efficiency
b) degree of reaction
c) Rankine efficiency (Ans)
d) relative efficiency

50. Reciprocating compressors are provided with
a) simple disc/plate valve (Ans)
b) poppet valve
d) solenoid valve

51. The gross head available to hydraulic power plant is 100m. The utilised head in the runner of the hydraulic turbine is 72 m. If the hydraulic efficiency of the turbine is 90% , the pipe friction head is estimated to be
a) 20 m (Ans)
b) 18 m
c) 16.2 m
d) 1.8 m

52. Which one of the following pairs of formulae represents the specific speeds of turbine and pump respectively ? (Notations have their usual meanings)
a) NQ 1/2 and NP1/2
H3/4 H5/4
b) NQ 1/2 and NP1/2
H3/4 H3/4
c) NP1/2 and NQ1/2
H3/4 H5/4
d) NP 1/2 and NQ1/2 (Ans)
H5/4 H3/4

53. The outer surface of a long cylinder is maintained at constant temperature. The cylinder does not have any heat source
The temperature in the cylinder will
c) be independent of radius (Ans)

54. A composite plane wall is made up of two different materials of the same thickness and having a thermal conductivities of k1 and k2 respectively. The equivalent thermal conductivity of the slab is
a) k1+k2

b) k1k2

c) k1+k2 (Ans)
k1k2

d) 2k1k2
k1+k2

55. A copper wire of radius 0.5 mm is insulated with a sheathing of thickness 1 mm having a thermal conductivity of 0.5 W/m-K. The outside convective heat transfer coefficient is 10W/m2-K. If the thickness of insulation sheathing is raised by 10 mm, then the electrical current-carrying capacity of the wire will
a) increase
b) decrease
c) remain the same (Ans)
d) vary depending upon the electrical conductivity of the wire

56. For the fully developed laminar flow and heat transfer in a uniformly heated long circular tube, if the flow velocity is doubled and the tube diameter is halved, the heat transfer coefficient will be
a) double of the original value
b) half of the original value (Ans)
c) same as before
d) four times of the original value

57. Heat transfer by radiation between two grey bodies of emissivity e is proportional to (notations have their usual meanings)
a) (Eb – J)
(I – e)
b) (Eb – J) (Ans)
(I – e) /e
c) (Eb – J)
(I – e)2
d) (Eb – J)
(I – e2)

58. The Nusselt number is related to Reynolds number in laminar and turbulent flows respectively as
a) Re-1/2 and Re0.8
b) Re1/2 and Re0.8 (Ans)
c) Re-1/2 and Re-0.8
d) Re1/2 and Re-0.8

59. In respect of free convection over a vertical flat plate the Nusselt number varies with Grashof number ‘Gr’ as
a) Gr and Gr1/2 for laminar and turbulent flows respectively (Ans)
b) Gr 1/2 and Gr1/3 for laminar and turbulent flows respectively
c) Gr1/4 and Gr1/3 for laminar and turbulent flows respectively
d) Gr1/3 and Gr1/4 for laminar and turbulent flows respectively

60. The enthalpies at the beginning of compression, at the end of compression and at the end of condensation are respectively 185 kJ/kg and 85 kJ/kg. The COP of the vapour compression refrigeration system is
a) 0.25
b) 5.4
c) 4 (Ans)
d) 1.35

61. The COP of a heat pump ßHP and the COP of a refrigerator ßRef are related as
a) ßHP + ßRef
b) ßHP – ßRef = 1 (Ans)
c) ßRef – ßHP = 1
d) ßHP – ßRef = 0

62. The discharge pressure of the compressor in the refrigeration system goes up due to the
a) lower volumetric efficiency of the compressor
b) formation of scale in the condenser (Ans)
c) large size of the condenser
d) undercharge of the refrigerant

63. The leakage in a Freon-based refrigeration system can be detected by using a/an
a) oxy-acetylene torch
b) halide torch (Ans)
c) sulphur torch
d) blue litmus paper

64. When warm saturated air is cooled
a) excess moisture condenses (Ans)
b) excess moisture condenses but relative humidity remains unchanged
c) excess moisture condenses and specific humidity increases but relative humidity remains unchanged.
d) specific humidity increases and relative humidity decreases
65. When dry-bulb and wet-bulb temperature are identical, it means that the
a) air is fully saturated and dew-point temperature has reached
b) air is fully saturated (Ans)
c) dew-point temperature has reached and humidity is 100%
d) partial pressure of water vapour is equal to total pressure

66. The desirable air velocity in the occupied zone for comfort for summer air-conditioners is in the range of
a) 6-7 m/minute
b) 4-5m/minute
c) 2-3 m/minute
d) 0.5-1.5 m/minute (Ans)

67. An air-conditioned room of volume 10 cm3 has infiltration of air equivalent to 3 air changes. Density of air is 1.2 kg/3, specific heat Cp is 1 kJ/kg-K and temperature difference between room and ambient air is 20K. The sensible heat load due to infiltrated air is
a) 60 kJ/hr
b) 12 kJ/hr
c) 6 kW
d) 0.2 k W (Ans)

68. If heat and mass transfer take place simultaneously, the ratio of heat transfer coefficient to the mass transfer coefficient is a function of the ratio of
a) Schmidt and Reynolds numbers (Ans)
b) Schmidit and Prandtl numbers
c) Nusselt and Lewis number
d) Reynolds and Lewis numbers

69. Consider the following statements :
The typical air velocities in the ducts of air-conditioning systems are
(i) lower in residential buildings as compared to those of public buildings
(ii) higher in residential buildings as compared to those of public buildings
(iii) higher in industrial buildings as compared to those of public buildings
(iv) equal in all types of buildings
Which of these statements is/are correct ?
a) (i) alone
b) (i) and (iii) (Ans)
c) (ii) and (iii)
d) (iv) alone

70. Consider the following parameters :
(i) Dry-bulb temperature
(ii) Humidity ratio
(iii) Air velocity
Which of these parameters are taken into account for determining effective temperature for human comfort ?
a) (i) and (ii)
b) (i) and (iv)
c) (ii), (iii) and (iv)
d) (i), (ii) and (iii) (Ans)

BSNL TTA question papers
BSNL TTA question papers

1. Modern capacitors which have high capacitance in small size use a dielectric of
(a) Paper
(b) Rubber
(c) Ceramic (Ans)
(d) Mylar

2. The Maximum spectral response of the germanium and silicon is in the
(a) infrared region
(b) ultraviolet region (Ans)
(c) visible region
(d) x-ray region

3. For an insulating material, dielectric strength and dielectric loss should be respectively
(a) high and high
(b) low and high
(c) high and low (Ans)
(d) low and low

4. In a distortion factor meter, the filter at the front end is used to suppress
(a) odd harmonics
(b) even harmonics
(c) fundamental component (Ans)
(d) dc component

5. The coefficient of coupling between two air core coils depends on
(a) mutual inductance between two coils only
(b) self inductances of the two coils only
(c) mutual inductance and self inductances of the two coils (Ans)
(d) none

6. For a parallel plate capacitor which is being charged out of the following the incorrect statement is
(a) Energy stored in the capacitor does not enter it through the connecting wire through the space around the wires and plates of capacitor
(b) Rate at which energy flows into this volume is equal to the integration of the poynting vector over the boundary of the volume between the plates.
(c) The poynting vector points everywhere radially outward of the volume between plates. (Ans)
(d) The poynting vector points everywhere radially into the volume between the plates.

7. The presence of alkali oxides in alumino silicate ceramics is likely to result in dielectric breakdown due to
(a) Polarization
(b) Conductivity (Ans)
(c) Structural homogeneties
(d) Ionization

8. Which of the following will serve as a donor impurity in silicon
(a) Boron
(b) Indium
(c) Germanium
(d) Antimony (Ans)

9. Electrical contact materials used in switches, bruses and relays must possess
(a) high -thermal conductivity and high melting point (Ans)
(b) Low thermal conductivity and low melting point
(c) High thermal conductivity and low melting point
(d) Low thermal conductivity and high melting point

10. An SCR can only be turned off via it’s
(a) cathode
(b) anode (Ans)
(c) gates
(d) none

11. Gold is often diffused into silicon PN junction devices to
(a) increase the recombination rate
(b) reduce the recombination rate (Ans)
(c) make silicon a direct gap semiconductor
(d) make silicon semi-metal

12. With n nodes and b branches a network will have

13. When a network has 10 nodes and 17 branches in all then the number of node pair voltages would be
(a) 7
(b) 9 (Ans)
(c) 10
(d) 45

14. In any atom the potential energy of an orbiting electron is
(a) always positive
(b) always negative (Ans)
(c) sometime positive, sometime negative
(d) numerically less than its kinetic energy.

15. A deplition MOSFET differs from a JFET in the sense that it has no
(a) channel
(b) gate
(c) P-N junctions (Ans)
(d) Substrate

16. The advantage of a semiconductor strain gauge over the wire round strain gauge is that
(a) it is more sensitive (Ans)
(b) it is more linear
(c) it is less temperature dependent
(d) it’s cost is low

17. Barrier potential in a P-N junction is caused by
(a) thermally generated electrons and holes
(b) diffusion of majority carriers across the junction
(c) migration of minority carriers across the junction (Ans)
(d) flow of drift current

18. when an NPN transistor is properly biased then most of the electrons from the emitter
(a) recombine with holes in the base
(b) recombine in the emitter itself
(c) pass through the base to the collector (Ans)
(d) are stopped by the junction barrier

19. The deplition voltage for silicon diode at µo bias is
(a) 0.5 volt
(b) 0.3 volt
(c) 0.7 volt (Ans)
(d) 1.1 volt

20. A UJT can
(a) be triggered by any one of it’s three terminals
(b) not be triggered
(c) be triggered by two of its three terminal only (Ans)
(d) be triggered by all of its terminals only.

21. The energy of electric field due to a spherical charge distribution of radium r and uniform charge density in vacuum is

22. Maxwells divergence equation for the magnetic field is given by
23. When a short grounded vertical antenna has a length L which is 0.05 1 at frequency f and if it’s radiation resistances at f is R Ohms, then its radiation resistance at a frequency 2f will be
(a) R/2 ohms
(b) R ohms
(c) 2R ohms
(d) 4R ohms (Ans)

24. In a cylindrical cavity resonator, the two modes which are degenerate would include
(a) TE111 and TM111
(b) TE011 and TM011
(c) TE022 and TM111
(d) TE111 and TM011 (Ans)

25. When an antenna of input resistance 73 ohm is connected to a 50-ohm line and if the losses are ignored then its efficiency will be nearly
(a) 0.19
(b) 0.81 (Ans)
(c) 0.97
(d) 1.19

26. The transformer utilization factor of full wave bridge rectifier is
(a) 0.812
(b) 0.286 (Ans)
(c) 0.693
(d) 0.782

27. When a dominant mode wage guide not terminated in its characteristic impedance is excited with a 10 GHz signal then if d is the distance between two successive minima of the standing wave in the guide then
(a) d = 1.5 cm (Ans)
(b) d is less than 1.5 cm
(c) d is greater than 1.5 cm
(d) d= 3cm

28. A two port network having a 6 dB loss will give
(a) an output power which is one-quarter of the input power (Ans)
(b) an output power which is one-half of the input power
(c) an output voltage which is 0.707 of the input voltage
(d) an output power which is 0.707 of the input power

29. While transporting a sensitive galvanometer
(a) the terminals are kept shorted
(b) critical damping resistance is connected across the terminals (Ans)
(c) the terminals are kept open circuited
(d) it does not matter as to what is connected across the terminals

30. A T type attenuator is designed for an attenuation of 40 dB and terminating resistance of 75 ohms. which of the following values represent full series arm R1 and shunt arm R2?
1. R1 = 147 ? 2. R1 = 153 ?
3. R1 = 1.5? 4. R2 = 3750 ?
(a) 1 and 3 (Ans)
(b) 1 and 4
(c) 2 and 3
(d) 2 and 4

31. For a transmission line, the characteristic impedance with inductance 0.294 ?H/m and capacitance 62pF/m is
(a) 49 ?
(b) 60 ?
(c) 70 ? (Ans)
(d) 140 ?

32. When the graph of a network has six branches with three tree branches then the minimum number of equations required for the solution of the network is
(a) 2
(b) 3 (Ans)
(c) 4
(d) 5

33. Consider the following statement of a 2-port network
(1) Z11 = Z22 (2) h12 = h21
(3) Y12 = -Y21 (4) BC – AD = -1
then the network is reciprocal if and only if
(a) 1 and 2 are correct
(b) 2 and 3 are correct
(c) 3 and 4 are correct
(d) 4 alone is correct (Ans)

34. As a network contain only independent current sources and resistors then if the values of all resistors are doubled then the values of the node voltages are
(a) will become half
(b) will remain unchanged
(c) will become double (Ans)
(d) cannot be determined unless the circuit configuration and the values of the resistors are known.

35. A iron cored choke is a
(a) A Linear and active device
(b) Non linear and passive device (Ans)
(c) Active device only
(d) Linear device only

36. Poynting vector wattmeter is based on
(a) Seebeck effect
(b) Ferranti effect
(c) Induction effect (Ans)
(d) Hall effect

37. Which one of the following is not a transducer in the true sense?
(a) Thermocouple
(b) Piezoelectric pick-up
(c) Photo voltaic cell
(d) LCD (Ans)

38. The term used to denote a static device that converts ac to dc, dc to ac, dc to dc or ac to ac is
(a) Converter system (Ans)
(b) Inverter
(c) Chopper
(d) Thyristor

39. When a dipole antenna of 1/8 length has an equivalent total loss resistance of 1.5 Watt then the efficiency of the antenna is
(a) 0.89159 %
(b) 8.9159 %
(c) 89.159 % (Ans)
(d) 891.59 %

40. In commercial FM broadcasting, the maximum frequency deviation is normally
(a) 5 KHz
(b) 15 KHz
(c) 75 KHz (Ans)
(d) 200 KHz
BSNL-

PART 1 GENERAL ABILITY
1) Operation Flood is Related To

ANS: Production of MilK 2) Capital of DaDra Nagar Haveli ANS: Silvasa 3) Suger Bowl Of India ANS: Uttar Pradesh 4) Minimum Age To Became President of India ANS: 35 year 5) BANKER OF BANK ANS: RBI 6) Oldest Mountain In India ANS: Araavali 7) Monsoon affected State ANS: Orrisa 8) Vidya Sagar Setu ANS: Hoogly river 9) Peroid of RajyaSabha ANS: 6 year 10) Our Indian Constitution pass By RAJYA SABHA ANS: 26 NOVEMBER 1949 PART 2 BASIC ENGINEERING 1) A+A(BAR) ANS: 1 2) A+AB ANS:A 3) FIND THE GATE ANS: A B Y 0 1 1 1 0 1 1 1 0 4) (3AB)16 =2979 5) O/P of EXNOR Gate ANS : A B Y 0 0 1 0 1 0 1 0 0 1 1 1 6) ASCII is a ANS: 7 unit Code 7) In LASER ” S” Stands for ANS: STIMULATED 8) Energy Band GAp of Silicon ANS: 1.1 ev 9) Wave Guide act as ANS: High Pass Filter 10) Bode Plot Is applicable to ANS: Minimum Phase Network 11) Efficiancy of CLASS B PUSH PULL Amplifier ANS: 78.5% 12) Ideal Voltage Controlled Current sourse has ANS: Ri = infinity R0= ZERO 13) Break Down Voltage of SILICON ANS: 0.6 14) A Darling Pair Consist of ANS: Both Collector 15) Sampling Theorm Fibd application In ANS: PCM 16) Poynting Vector ANS: P=E*H 17) The Speaker used in Telephone RX is ANS: Fixed Coil Type 18) Measurment of High Q Inductence AND: HAYS BRIDGE 19) Measurment of Very High Resistance ANS: MEGGER Similar Categories more HCL Mu-Sigma TCS Amazon CTS
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BSNL Electronics and Electrical Questions

BSNL Model Question papers with answers and detailed explanations to prepare for upcoming JTO and Technicians examintion

BSNL electronics and electrical solved question papers

1. To neglect a voltage source, the terminals across the source are

(A) open circuited

(B) short circuited (Ans)

(C) replaced by some resistance

(D) replaced by an inductor

2. Current I0 in the given circuit will be

(A) 10 A

(B) 3.33 A (Ans)

(C) 20 A

(D) 2.5 A

Solution : RT = 2 + 2 || [1 + (2 || 2)]

= 2 + 2 || (1 + 1)

= 2 + 2 || 2 = 2 + 1 = 3 O

So I = 40 A
3

By current division I0 = 1 * 1 * 40 = 10 A
2 2 3 3

I0 = 3.33 A

3. In a resonant circuit, the power factor at resonance is

(A) zero

(B) unity (Ans)

(C) 0.5

(D) 1.5

4. In the given circuit voltage V is reduced to half. The current will become

(A) I/2 (Ans)

(B) 2 I

(C) 1.5 I

(D) I / vR2 + (XL + XC)2

Solution : I a V if V reduced half current becomes I .
2

5. The function 3 s has
(s + 1) (s + 2)

(A) one zero, two poles (Ans)

(B) no zero, one pole

(C) no zero, two poles

(D) one zero, no pole

Solution : G (s) = 3s has one zero at s = 0 and two poles at s = – 1, – 2.
(s + 1) (s + 2)

6. One electron volt is equivalent to

(A) 1.6 * 10-10 J

(B) 1.6 * 10-13 J

(C) 1.6 * 10-16 J

(D) 1.6 * 10-19 J (Ans)

7. Which of the following is donor impurity element ?

(A) Aluminium

(B) Boron

(C) Phosphorous (Ans)

(D) Indium.

8. The diameter of an atom is of the order

(A) 10-6 m

(B) 10-10 m (Ans)

(C) 10-15 m

(D) 10-21 m

9. The following Figure represents

Image – BSNL- MB (J.T.O.) RE 2001 – Part A – Qno. 9

(A) LED (Ans)

(B) Varistor

(C) SCR

(D) Diac

10. If the d.c. valve of a rectified output is 300 V and peak to peak ripple voltage is 10 V, the ripple factor is

(A) 1.18%

(B) 3.33% (Ans)

(C) 3.36%

(D) 6.66%

Solution : rms value of output

= v3002 + 102 = 300.166 V

Average value = 300 V

Form factor RMS value = 300.166 = 1.00055.
Average value 300

Ripple factor = v(Form factor)2 – 1

= v(1.0005)2 – 1 = 0.0333

= 3.33%.

11. Full wave rectifier output has ripple factor of

(A) 1.11 (Ans)

(B) 1.21

(C) 1.41

(D) 1.51

12. In a common base connection IE = 2 mA, IC = 1.9 mA. The value of base current is

(A) 0.1 m (Ans)

(B) 0.2 mA

(C) 0.3 mA

(D) zero

Solution : IE = 2 mA IC = 1.9 mA

Ib = IE – IC = (2 – 1.9) = 0.1 mA.

13. For the action of transistor the base region must be

(A) P-type material

(B) N-type material

(C) very narrow (Ans)

(D) highly doped

14. Compared to a CB amplifier the CE amplifier has higher

(A) current amplification

(B) output dynamic resistance

(C) leakage current

(D) input dynamic resistance

(E) all of the above (Ans)

15. When a transistor is biased to cut-off its Y is

(A) 0.5

(B) 0

(C) 1.0 (Ans)

(D) 0.8

16. An ideal voltage amplifier should have

(A) Ri = 0, R0 = 0

(B) Ri = 0, R0 = ¥

(C) Ri = ¥, R0 = 0 (Ans)

(D) Ri = 0, R0 = ¥

17. Barichausen criterion for sustained oscillator is

(A) Aß = 1 Ð00 (Ans)

(B) Aß = 0

(C) Aß = 1 Ð1800

(D) A = 1/vß

18. The value of plastic capacitance for a triode may range from

(A) 2 µF to 12 µF

(B) 20 µF to 120 µF

(C) 2 pF to 12 pF (Ans)

(D) 20 pF to 120 pF

19. A colpitts oscillator uses

(A) tapped coil

(B) inductive feedback

(C) tapped capacitance (Ans)

(D) no tuned LC circuit

20. A typical frequency for a RC feedback oscillator is

(A) 1 KHz (Ans)

(B) 100 MHz

(C) 1000 MHz

(D) 1 GHz

21. In pulse transmitter the ratio of time on to time off is called

(A) efficiency

(B) duty cycle (Ans)

(C) base

(D) bandwidth

22. FM broadcast band generally lies in

(A) LF

(B) HF

(C) VHF (Ans)

(D) SHF

23. The following filter is generally used in SSB generation

(A) active filter

(B) mechanical filter (Ans)

(C) LC filter

(D) crystal filter

24. Which is a digital communication system ?

(A) FM

(B) AM

(C) PCM (Ans)

(D) PAM

25. A transistor is basically an amplifying device for

(A) power

(B) voltage

(C) current (Ans)

(D) all of these

BSNL PAPER ON 20TH JUNE,2008

1. For a parallel plate capacitor which is being charged out of the following the incorrect statement isa)Energy stored in the capacitor does not enter it through the connecting wire through the space around the wires and plates of capacitor.b) Rate at which energy flows into this volume is equal to the integration of the pointing vector over the boundary of the volume between the plates.
c) The pointing vector points everywhere radially outward of the volume between plates.
d) The pointing vector points everywhere radially into the volume between the plates.

2. The presence of alkali oxides in alumino silicate ceramics is likely to result in dielectric breakdown due to
a) Polarization
b) Conductivity
c) Structural homogeneties
d) Ionization 3. Which of the following will serve as a donor impurity in silicon
a) Boron b) Indium c) Germanium d) Antimony 4. Electrical contact materials used in switches, brushes and relays must possess
a) High thermal conductivity and high melting point
b) Low thermal conductivity and low melting point
c) High thermal conductivity and low melting point
d) Low thermal conductivity and high melting point 5. The Maximum spectral response of the germanium and silicon is in the
a) infrared region b) ultraviolet region c) visible region d) x-ray region 6. For an insulating material, dielectric strength and dielectric loss should be respectively
a) high and high b) low and high c) high and low d) low and low 7. In a distortion factor meter, the filter at the front end is used to suppress
a) odd harmonics b) even harmonics c) fundamental component d) dc component 8. The coefficient of coupling between two air core coils depends on
a) mutual inductance between two coils only b) self inductances of the two coils only
c) mutual inductance and self inductances of the two coils
d) none 9. Modern capacitors which have high capacitance in small size use a dielectric of
a) paper b) rubber c) ceramic d) Mylar
10. In any atom the potential energy of an orbiting electron is
a) always positive
b) always negative
c) sometime positive, sometime negative
d) numerically less than its kinetic energy 11. A DE MOSFET differs from a JFET in the sense that it has no –
a) channel b) gate c) P-N junctions d) substrate 12. The advantage of a semiconductor strain gauge over the normal strain gauge is that
a) it is more sensitive
b) it is more linear
c) it is less temperature dependent
d) it’s cost is low 13. Barrier potential in a P-N junction is caused by
a) thermally generated electrons and holes
b) diffusion of majority carriers across the junction
c) migration of minority carriers across the junction
d) flow of drift current 14. When an NPN transistor is properly biased then most of the electrons from the emitter
a) recombine with holes in the base
b) recombine in the emitter itself
c) pass through the base to the collector
d) are stopped by the junction barrier 15. The value of r when a transistor is biased to cut off is –
a) 0.5 b) 0 c) 1.0 d) 0.8 16. A UJT can
a) be triggered by any one of it’s three terminals
b) not be triggered
c) be triggered by two of its three terminal only
d) be triggered by all of its terminals only 17. An SCR can only be turned off via it’s
a) cathode b) anode c) gates d) none 18. Gold is often diffused into silicon DN junction devices to
a) increase the recombination rate
b) reduce the recombination rate
c) make silicon a direct gap semiconductor
d) make silicon semi-metal 19. With n nodes and b branches a network will have
a) (b + n) links b) b – n + 1 links c) b – n – 1 links d) b + n + 1 links 20. When a network has 10 nodes and 17 branches in all then the number of node pair voltages would be
a) 7 b) 9 c) 10 d) 45 21. A two port network having a 6 dB loss will give
a) an output power which is one – quarter of the input power
b) an output power which is one – half of the input power
c) an output voltage which is 0.707 of the input voltage
d) an output power which is 0.707 of the input power 22. While transporting a sensitive galvanometer –
a) the terminals are kept shorted
b) critical damping resistance is connected across the terminals
c) the terminals are kept open circuited
d) it does not matter as to what is connected across the terminals 23. A T type attenuator is designed for an attenuation of 40 dB and terminating resistance of 75 ohms. Which of the following values represent full series and R1 and shunt arm R2 ?
1. R1 = 147W 2. R1 = 153W
3. R2 = 1.5W 4. R2 = 3750W
a) 1 and 3 b) 1 and 4 c) 2 and 3 d) 2 and 4 24. For a transmission line, the characteristic impedance with inductance 0.294mH/m and capacitance 60pF/m is
a) 49w b) 60w c) 70w d) 140w 25. When the graph of a network has six branches with three tree branches then the minimum number of equations required for the solution of the network is
a) 2 b) 3 c) 4 d) 5 26. Consider the following statement for a 2-port network
1. Z11 = Z22 2. h12 = h21
3. Y12 = -Y21 4. BC – AD = -1
then the network is reciprocal if and only if
a) 1 and 2 are correct
b) 2 and 3 are correct
c) 3 and 4 are correct
d) 4 alone is correct 27. As a network contains only independent current sources and resistors then if the values of all resistors are doubled then the values of the node voltages are
a) will become half
b) will remain high
c) will become double
d) cannot be determined unless the circuit configuration and the values of the resistors are known 28. The energy of electric field due to a spherical charge distribution of radius r and uniform charge density d in vacuum is-
Ans. 5.4x109xQ2/r where Q=4/3(pie)r3d 29. Maxwell’s divergence equation for the magnetic field is given by
Ans. y 30. When a short grounded vertical antenna has a length L which is 0.05 l at frequency f and if it’s radiation resistances at f is R Ohms, then it’s radiation resistance at a frequency 2f will be
a) R/2 ohms b) R ohms c) 2R ohms d) 4R ohms 31. In a cylindrical cavity resonator, the two modes which are degenerate would include
a) TE111 and TM111
b) TE011 and TM011
c) TE022 and TM111
d) TE111 and TM011 32. When an antenna of input resistance 73 ohm is connected to a 50-ohm line and if the losses are ignored then it’s efficiency will be nearly
a) 0.19 b) 0.81 c) 0.97 d) 1.19 33. If an isolated conducting sphere in air has radius = 1/ 4pqe0 it capacitance will be
a) Zero b) IF c) 4pF d) OF 34. When a dominant mode wave guide not terminated in it’s characteristic impedance is excited with a 10 GHz signal then if ‘d’ is the distance between two successive minima of the standing wave in the guide then
a) d = 1.5 cm
b) d is less then 1.5 cm
c) d is greater than 1.5 cm
d) d = 3cm 35. When a dipole antenna of l/8 length has an equivalent total loss resistance of 1.5 W then the efficiency of the antenna is
a) 0.89159 % b) 8.9159 % c) 89.159 % d) 891.59 % 36. In commercial FM broadcasting, the maximum frequency deviation is normally
a) 5 KHz b) 15 KHz c) 75 KHz d) 200 KHz 37. Weins bridge is used for measurement of frequency in the applied voltage waveform is measurement of frequency in the applied voltage waveform is
a) sinusoidal b) square c) rectangular d) triangular 38. Strain gauge is
a) not a transducer
b) an active transducer
c) not an electronic instrument
d) none 39. A high Q coil has
a) large band width b) high losses c) low losses d) flat response
40. In the case of an instrument reading of 8.3V with a 0 to 150 voltmeter having a guaranteed accuracy of 1% full scale reading, the percentage limiting error is
a) 1.810% b) 0.181% c) 18.10% d) 0.0018% 41. The ‘h’ parameter equivalent circuit of a junction transistor is valid for
a) High frequency, large signal operation
b) High frequency, small signal operation
c) Low frequency, small signal operation
d) Low frequency, large signal operation 42. A system is causal if the output of any time depends only on –
a) Values of input in the past and in the future
b) Values of input at that time and in the past
c) Values of input at that time and in the future
d) None 43. A iron cored choke is a
a) Linear and active device
b) Non linear and passive device
c) Active device only
d) Linear device only 44. Pointing vector wattmeter uses
a) Seebeck effect b) Ferranti effect c) Induction effect d) Hall effect 45. Which one of the following is not a transducer in the true sense ?
a) Thermocouple b) Piezoelectric pick – up
c) Photo voltaic cell d) LCD 46. The term used to denote a static device that converts ac to dc, dc to ac, dc to dc or ac to ac is
a) Converter system b) Inverter c) Chopper d) Thyristor 47. It is an unidirectional device that blocks the current flow from cathode to anode
a) SCR b) PCR c) VCR d) DCR 48. An ideal constant current source is connected in series with an ideal constant voltage source. Considering together the combination will be a
a) constant voltage source
b) constant current source
c) constant voltage and a constant current source or a constant power source
d) resistance 49. Anode current in an thyristor is made up of
a) electrons only b) electrons or holes c) electrons and holes d) holes only 50. For a pulse transformer, the material used for its core and the possible turn ratio from primary to secondary are respectively
a) ferrite : 20 : 1
b) laminated iron : 1 : 1
c) ferrite : 1 : 1
d) powdered iron : 1 : 1 51. A converter which can operate in both 3 pulse and 6 pulse modes is a
a) 1 phase full converter
b) 3 phase half wave converter
c) 3 phase semi converter
d) 3 phase full converter 52. A single phase CSI has capacitor C as the load. For a constant source current, the voltage across the capacitor is
a) square wave b) triangular wave c) step function d) pulsed wave 53. A single phase full wave midpoint thyristor converter uses a 230/200V transformer with center tap on the secondary side. The P.I.V per thyristor is
a) 100V b) 141.4V c) 200V d) 282.8V 54. In dc choppers for chopping period T, the output voltage can be controlled by FM by varying
a) T keeping Ton constant
b) Ton keeping T constant
c) Toff keeping T constant
d) None of the above 55. From the hot metal surface electrons escape because
a) of change of state from metal to gas due to heat.
b) of change of stats from gas to metal.
c) the energy supplied is greater than the work function
d) the energy is greater than Fermi level. 56. The most common device used for detection in radio receivers is –
a) amplifier b) triode c) diode d) transistor 57. In a full wave rectifier the negative point in a circuit is
a) Either cathode
b) Either anode
c) The central tap on the high voltage secondary
d) Either plate 58. Negative feedback amplifier has a signal corrupted by noise as its input. The amplifier will
a) Amplify the noise as much as the signal
b) Reduce the noise
c) Increase the noise
d) Not effect the noise 59. Match the given feedback circuit with it’s proper nomenclatures

a) Current series feedback
b) Current shunt feedback
c) Voltage series feedback
d) Voltage shunt feedback

60. Class A amplifier is used when
a) No phase inversion is required
b) Highest voltage gain is required
c) dc voltages are to be amplified
d) Minimum distortion is desired

61. Identify the correct match for the given transistor

a) Enhancement type P channel MOSFET
b) Depletion type N channel MOSFET
c) Enhancement type N channel MOSFET
d) Depletion type P channel MOSFET
62. In case a signal band limited to fm is sampled at a rate less than 2fm, the constructed signal will be
a) Distortionless
b) Small in amplitude
c) Having higher frequencies suppressed
d) Distorted 63. Quad 2 input AND gates IC No is
a) 7411 b) 7404 c) 7400 d) 7408 64. Registers in which data is entered or taken out in serial form are referred as
a) left shift register b) right shift register c) shift registers d) none of the above
65. The expression ABC can be simplified to
Ans. A + B + C
66. An ideal power supply consist of
a) Very small output resistance
b) Zero internal resistance
c) Very large input resistance
d) Very large output resistance
67. The linearity error for a digital input is indicated by
68. Register and counters are similar in the sense that they both
a) count pulses
b) store binary operation
c) shift registers
d) made from an array of flip flops and gates integrated on a single chip
69. In the 8421 BCD code the decimal number 125 is written as
a) 1111101 b) 0001 0010 0101 c) 7D d) None of the above
70. In D/A converter, the resolution required is 50mv and the total maximum input is 10v. The number of bits required is
a) 7 b) 8 c) 9 d) 200
71. On differentiation unit impulse function results in
a) Unit parabolic function.
b) Unit triplet.
c) Unit doublet.
d) Unit ramp function.
i. Routh Hermitz`s criterion is in time domain.
ii. Root locus plot is in time domain.
iii. Bode plot is in frequency domain.
iv. Nyquist criterion is in frequency domain.
a) 2, 3, and 4 are correct
b) 1, 2 and 3 are correct
c) 3 and 4 are correct
d) All four are correct.
73. The maximum phase shift that can be provided by a lead compensator with transfer function.
a) 150 b) 450 c) 300 d) 600
74. The correct sequence of steps required to improve system stability is
a) Insert derivative action, use negative feedback, reduce gain.
b) Reduce gain, use negative feedback, insert derivative action.
c) Reduce gain, insert derivative action, use negative feedback.
d) Use negative feedback, reduce gain, insert derivative action.
75. Identity slope change at w = 10 of the magnitude v/s frequency characteristic of a unity feedback system with the following open-loop transfer function
a) –40dB/dec to –20dB/dec
b) 40dB/dec to 20dB/dec
c) –20dB/dec to –40dB/dec
d) 40dB/dec to –20dB/dec
76. In the feedback control system the loop transfer function is given by
Number of asymptotes of its root loci is
a) 1 b) 2 c) 3 d) 4
77. In a closed – loop transfer function
the imaginary axis intercepts of the root loci will be
78. Considering the following statement :
In a magic tee
1. the collinear arms are isolated from each other
2. one of the collinear is isolated from the E-arm
3. one of the collinear arm is isolated from the H-arm
4. E-arm and H-arm are isolated from each other.
Of these statements
a) 1 and 2 are correct
b) 1 and 3 are correct
c) 1 and 4 are correct
d) 2 and 3 are correct
79. In 1965 first geostationary satellite was launched called
a) ANIK
b) EARLY BIRD (Intel sat -1)
c) WESTAR
d) MOLNIYA
80. — watt of power is received from sun per m2 surface area of a geosynchronous satellite
a) 100 b) 500 c) 2000 d) 1000
81. The ripple factor in an LC filter
a) Increases with the load current
b) Increases with the load resistance
c) Remains constant with the load current
d) Has the lowest value
82. In different parts of the country identical telephone numbers are distinguished by their
a) Language digits b) Access digits c) Area codes d) Central office codes
83. Amplitude modulation is used for broadcasting because
a) it is move noise immune than other modulation systems
b) compared with other systems it requires less transmitting power
c) its use avoids receiver complexity
d) no other modulation system can provide the necessary bandwidth for high fidelity
84. The amplifiers following the modulated stage in a low level modulation AM system be
a) linear amplifier
b) harmonic generators
c) class C power amplifiers
d) class B untuned amplifiers
85. In a radar system maximum unambiguous range depends on
a) maximum power of the transmitter
b) pulse repetition frequency
c) width of the transmitted pulse
86. In composite video waveform the function of the serrations, is to
a) equalize the charge in the integrator before the start of vertical retrace.
b) help vertical synchronization
c) help horizontal synchronization.
d) simplify the generation of the vertical sync pulse
87. The frequency range 30MHz – 300MHz is
a) medium frequency
b) very high frequency
c) super high frequency
d) Infrared frequency
88. Which wave cannot exist inside wave guide
a) TE b) TM c) TEM d) HE
89. Ionosphere layer of earth is situated at
a) upto 18kms from earth
b) from 18 to 70 km
c) 70 to 500 km
d) above 500 km
90. A two cavity klystron tube is a
a) velocity modulated tube
b) frequency modulated tube
c) Amplitude modulated tube
d) simple triode
91. As the thermal noise get doubled due to the increase in a resistance the noise power get
a) doubled b) quadrupted c) unchanged d) halved
92. Which one is a cross field tube
a) Klystron b) Reflex Klystron c) Magnetron d) TWT
93. The degree of coupling depends on
a). size of hole
b). location of holes
c). size and location of holes
d). not depend on size or location of hole
94. The thermal noise depends on
a) direct current through device
b) resistive component of resistance
c) reactive component of impedance
95. The charge on a hole is
Ans. 1.6×10-19
a) is tuned above the stations incoming frequency
b) amplifies the output of local oscillator
c) is fixed tuned to one particular frequency
d) can be tuned to various isolate frequencies
97. A duplexer is used to
1) couple two antennas to a transmitter without interference
2) isolate the antenna from the local oscillator
3) prevent interference between two antennas connected to a receiver
4) use an antenna for reception or transmission without interference
98. Intel’s 8085 microprocessor chip contains
a) seven 8 bit registers
b) 8 seven bits registers
c) seven 7
d) eight 8
99. Boolean algebra is based on
a) numbers b) logic c) truth d) symbols
100. When A = 0, B = 0, C = 1 then in 2 input logic gate we get – – gate
a) XOR b) AND c) NAND d) NOR
101. With the beginnings of space travel, we entered a new – –
a) Era of great history b) List c) Book d) Year
102. An – – though it mourns the death of someone, need not be sad.
a) Funny poem b) Newspaper article c) Orthodox talk d) Elegy
103. If stare is glance so gulp is
a) Sip b) Tell c) Salk d) Admire
104. He hardly works means
a) The work is hard
b) He is hard
c) The work is easy
d) He works very little
105. Give the opposite word for pulchritude
a) antipathy b) unsightliness c) inexperience d) languor
106. Nanometre is – – – – part of a metre.
a) Millionth b) Ten millionth c) Billionth d) Ten billionth
107. Malaria affects
a) Liver b) Spleen c) Intestine d) Lungs
108. Sindhu Rakshak is a/an
a) Aircraft carrier
b) Submarine
c) Multiple-purpose fighter
d) Anti-aircraft gun
109. With which subject is “Dada Saheb Phalke Award” associated?
a) Best film director
b) Best musician
c) Best documentary
d) Best work relating to promotion of Indian film Industry
110. Who developed the branch of mathematics known as Calculus?
a) Aryabhatta b) Newton c) Einstein d) Archimedes
111. In which state is Kanha Park situated?
a) M.P. b) U.P. c) Assam d) W. Bengal
112. Which day is observed as Human Rights Day?
a) 24th October b) 4th July c) 8th August d) 10th December
113. The Kailash Temple at Ellora is a specimen of
a) Gupta architecture
b) Rashtrakuta architecture
c) Chalukya architecture
d) Chola architecture
114. When the two Houses of Parliament differ regarding a Bill then the controversy is solved by
a) Joint sitting of the two Houses
b) President of India
c) Prime Minister of India
d) By a special committee for the purpose
115. Which of the following is not the work of Kalidasa?
a) Meghdoot
b) Raghuvansha
c) Sariputra Prakarma
d) Ritushamhara
116.Amir Khusro was the famous poet and aesthete of
a) Akbar the Great
b) Mahmud Ghaznvi
c) Shah Jahan
d) Alauddin Khilji
117. The words ‘Satyameva Jayate’ have been taken from
e) None of these
118. Which of the following countries was the first to develop a neutron bomb?
a) USA b) USSR c) China d) Pakistan
119. “Kathakali” dance is connected with
a) Kerala b) Rajasthan c) Uttar Pradesh d) Tamil Nadu 120. The term “Ashes” is associated with
a) Hockey b) Cricket c) Soccer d) none of these

BSNL JTO Placement Papers

PART I

1. Modern capacitors which have high capacitance in small size use a dielectric of
(A) paper (B) rubber (C) ceramic (D) Mylar

2. The Maximum spectral response of the germanium andsilicon is in the
(A) infrared region (B) ultraviolet region (C) visible region (D) x-ray region

3. For an insulating material, dielectric strength and dielectric loss should be respectively
(A) high and high (B) low and high (C) high and low (D) low and low.

4. In a distortion factor meter, the filter at the front end is used suppress
(A) odd harmonics (B) even harmonics (C) fundamental component (D) dc component

5. The coefficient of coupling between two air core coils depends on
(A) mutual inductance between two coils only (B) self inductances of the two coils only (C) mutual inductance and self inductances of the two coils (D) none

6. For a parallel plate capacitor which is being charged out of the following the incorrect statement is
(A) Energy stored in the capacitor does not enter it through the connecting wire through the space around the wires and plates of capacitor.
(B) Rate at which energy flows into this volume is equal to the integration of the poynting vector over the boundary of the volume between the plates.
(C) The poynting vector points everywhere radially outward of the volume between plates.
(D) The poynting vector points everywhere radially in to the volume between the plates.

7. The presence of alkali oxides in alumino silicate ceramics is likely to result in dielectric breakdown due to
(A) Polarization (B) Conductivity (C) Structural homogeneties (D) Ionization

8. Which of the following will serve as a donor impurity in silion
(A) Boron (B) Indium (C) Germanium (D) Antimony

9. Electrical contact materials used in switches, brushes and relays must possess
(A) high thermal conductivity and high melting point (B) Low thermal conductivity and low melting point
(C) High thermal conductivity and low melting point (D) Low thermal conductivity and high melting point.

10. An SCR can only be turned off via it’s
(A) cathode (B) anode (C) gates (D) none

11.Gold is often diffused into silicon PN junction devices to
(A) increase the recombination rate (B) reduce the recombination rate
(C) make silicon a direct gap semiconductor (D) make silicon semi-metal

12 Withn nodes andb branches a network will have

13. When a network has 10 nodes and 17 branches in all then the number of node pair voltages would be
(A) 7 (B) 9 (C) 10 (D) 45

14. In any atom the potential energy of an orbiting electron is
(A) always positive (B) always negative
(C) sometime positive, sometime negative (D) numerically less then its kinetic energy.

15. A delition MOSFET differs from a JFET in the sense that it has no
(A) channel (B) gate (C) P-N junctions (D) substrate

16. The advantage of a semiconductor strain gauge cover the wire round strain guage is that
(A) it is more sensitive (B) it is more linear (C) it is less temperature dependent
(D) it’s cost is low

17. Barrier potential in a P-N junction is caused by
(A) thermally generated electrons and holes (B) diffusion of majority carriers across the junction
(C) migration of minority carriers across the junction (D) flow of drift current.

18. When an NPN transistor is properly biased then most of the electrons from the emitter
(A) recombine with holes in the base (B) recombine in the emitter itself
(C) pass through the base to the collector (D) are stopped by the junction barrier

19. The deplition voltage for silicon diode atµ0 bias is
(A) 0.5 volt (B) 0.3 volt (C) 0.7 volt (D) 1.1 volt

20. A UJT can
(A) be triggered by any one of it’s three terminals (B) not be triggered
(C) be triggered by two of its three terminal only (D) be triggered by all of its terminals only.

21. The energy of electric field due to a spherical charge distribution of radiusr and inform charge density in vacuum is

22. Maxwells divergence equation for the magnetic field is given by
A. ?* B = 0
B. ?. B = 0
__ __
__ __
C. ?* B = p
D. ?. B = p

23. When a short grounded vertical antenna has a lengthL which is 0.05 1 at frequencyf and if it’s radiation resistances atf isR Ohms, then its radiation resistance at a frequency2f will be
(A)R/2 ohms (B)R ohms (C)2R ohms (D)4R ohms

24.In a cylindrical cavity resonator, the two modes which are degenerate would include
(A)TE111 andTM111
(B)TE011 andTM011
(C)TE022 andTM111
(D)TE111 and TM011

25. When an antenna of input resistance 73 ohm is connected to a 50-ohm line and if the losses are ignored then its efficiency will be nearly
(A) 0.19 (B) 0.81 (C) 0.97 (D) 1.19

26.The transformer utilization factor of full wave bridge rectifier is
(A) 0.812 (B) 0.286 (C) 0.693 (D) 0.782

27. When a dominant mode wave guide not terminated in its characteristic impedance is excited with a 10 GHZ signal then ifd is the distance between two successive minima of the standing wave in the guide then
(A)d = 1.5 cm (B)d is less then 1.5 cm (C)d is greater then 1.5 cm (D)d = 3cm

28. A two port network having a 6 dB loss will give
(A) an output power which is one – quarter of the input power (B) an output power which is one – half of the input power
(C) an output voltage which is 0.707 of the input voltage. (D) an output power which is 0.707 of the input power.

29. While transporting a sensitive galvanometer
(A) the terminals are kept shorted (B) critical damping resistance is connected across the terminals
(C) the terminals are kept open circuited (D) it does not matter as to what is connected across the terminals.

30. A T type attenuator is designed for an attenuation of 40 dB and terminating resistance of 75 ohms.
Which of the following values represent full series armR1 and shunt armR2?
1.R1 = 147 O 2.R1 = 153 O 3.R1 = 1.5 O 4.R1= 3750 O
(A) 1 and 3 (B) 1 and 4 (C) 2 and 3 (D) 2 and 4

31. For a transmission line, the characteristic impedance with inductance 0.294µH/m and capacitance 60pF/m is
(A) 49O (B) 60O (C) 70O (D) 140O

32. When the graph of a network has six branches with three tree branches then the minimum number of equations required for the solution of the network is
(A) 2 (B) 3 (C) 4 (D) 5

33. Consider the following statement for a 2-port network
1.Z11 =Z22
2.h12 =h21
3.Y12 = -Y21
then the network is reciprocal if and only if
(A) 1 and 2 are correct (B) 2 and 3 are correct (C) 3 and 4 are correct (D) 4 alone is correct.

34. As a network contains only independent current sources and resistors then if the values of all resistors are doubled then the values of the node voltages are
(A) will become half (B) will remain unchanged
(C) will become double (D) cannot be determined unless the circuit configuration and the values of the resistors are known.

35. A iron cored choke is a
(A) Linear and active device (B) Non linear and passive device (C) Active device only (D) Linear device only

36. Poynting vector wattmeter is based on
(A) Seebeck effect (B) Ferranti effect (C) Induction effect (D) Hall effect

37. Which one of the following is not a transducer in the true sense?
(A) Thermocouple (B) Piezoelectric pick-up (C) Photo voltaic cell (D) LCD.

38. The term used to denote a static device that converts ac to dc, de to ac, dc to dc or ac to ac is
(A) Converter system (B) Inverter (C) Chopper (D) Thyristor

39. When a dipole antenna of 1/8 length has an equivalent total resistance of 1.5 Watt then the efficiency of the antenna is
(A) 0.89159% (B) 8.9159% (C) 89.159% (D) 891.59%

40. In commercial FM broadcasting, the maximum frequency deviation is normally
(A) 5 KHz (B) 15 KHz (C) 75 KHz (D) 200 KHz

41. Weins bridge is used for measurement of frequency in the applied voltage waveform is measurement of frequency in the applied voltage waveform is
(A)sinusoidal (B) square (C) rectangular (D) triangular

42.Strain gauge is
(A) not a transducer (B) an active transducer (C) not an electronic instrument

43.A highQ coil has
(A) large band width (B) high losses (C) low losses (D) flat response

44. In the case of an instrument reading of 8.3 V with a 0 to 150 voltmeter having a guaranteed accuracy of 1% full scale reading, the percentage limiting error is
(A) 1.810% (B) 0.181% (C)12.45% (D) 0.0018%

45. The ‘h’ parameter equivalent circuit of a junction transistor is valid for
(A) High frequency, large signal operation (B) High frequency, small signal operation (C) Low frequency, large signal operation.

46. A system is causal if the output of any time depends only on
(A) Values of input in the past and in the future (B) Values of input at that time and in the past
(C) Values of input at that time and in the future (D) none

47. Form the hot metal surface electrons escape because
(A) of change of state from metal to gas due to heat. (B) of change of state from gas to metal (C) the energy supplied is greater than the work function (D) the energy is greater than Fermi level

48. The most common device used for detection in radio receivers is
(A) amplifier (B) triode (C) diode (D) transistor

49. In a full wave rectifier the negative point in a circuit is
(A) cathode (B) anode (C) The central tap on the high voltage secondary (D) plate.

50.Negative feedback amplifier has a signal corrupted by noise as its input. The amplifier will
(A) Amplify the noise as much as the signal (B) Reduce the noise (C) Increase the noise
(D) Not effect the noise

PART – II

51. It is an unidirectional device that blocks the current flow from cathode to anode
(A) SCR (B) PCR (C) VCR (D) DCR

52. An ideal constant current source is connected in series with an ideal constant voltage source. Considering together the combination will be a
(A) constant voltage source (B)constant current source
(C) constant voltage and a constant current source or a constant power source. (D) resistance

53. Anode current in an thyristor is made up of
(A) electrons only (B) electrons or holes (C) electrons and holes (D) holes only

54. For a pulse transformer, the material used for its core and the possible turn ration from primary to secondary are respectively
(A) ferrite : 20 : 1 (B) laminated iron : 1 :1 (C) ferrite : 1 : 1 (D) powered iron : 1: 1

55. A converter which can operate in both 3 pulse and 6 pulse mode is a
(A) 1 phase full converter (B) 3 phase half wave converter (C) 3 phase semiconverter (D) 3 phase full converter.

56. A single phase CSI has capacitor C as the load. For a constant source current, the voltage across the capacitor is
(A) square wave (B) triangular wave (C) step function (D) pulsed wave

57. a single phase full wave midpoint thyristor converter uses a 230/200V transformer with centre tap on the secondary side. The P.I.V per thyristor is
(A) 100V (B)141.4V (C)200V (D)282.8V

58. In dc choppers for chopping period T, the output voltage can be controlled by FM by varying
(A)T keepingTon constant (B)Ton keepingT constant
(C)Toff keepingT constant (D) None of the above

59.An ideal power supply consist of
(A) Very small output resistance (B) Zero Internal resistance
(C) Very large input resistance (D) Very large output resistance

60. The linearity error for a digital input is indicated by
(A) ? (B) ? (C) ? (D) e

61. In the 8421 BCD code the decimal number 125 is written as
(A)1111101 (B) 0001 0010 0101 (C) 7D (D) None of the bove

62. Match the given feedback circuit with its proper nomenclatures
(A) Current series feedback (B) Current shunt feedback
(C) Voltage series feedback (D) Voltage shunt feedback

63. Class A amplifier is used when
(A) No phase inversion is required (B) Highest voltage gain is required
(C) dc voltages are to be amplified (D) Minimum distortion is desired.

64. Identity the correct match for the given transister
(A) Enhancement type P channel MOSFET (B) Depletion type N channel MOSFET
(C) Enhancement type N channel MOSFET (D) Depletion type P channel MOSFET

65. In case a signal band limited to fermimeter is sampled at a rate less than 2 fermimeter, the constructed signal will be
(A) Distortionless (B) Small in amplitude (C) Having higher frequencies suppressed (D) Distorted

66.IC which has quad 2 input AND gates
(A) 7411 (B) 7404 (C)7400 (D) 7408

67. Registers in which data is entered or taken out in serial form are referred as
(A) left shift register (B) right shift register (C) shift registers (D) none of the above

68. The expression ABC can be simplified to
__ __ __
A. A B C
B. AB+BC+CA
__
__ __ __
C. AB+ C
C. A + B + C

(i) Routh Herwitz’s criterion is in time domain
(ii)Root locus plot is in time domain
(iii) Bode plot is in frequency domain
(iv) Nyquist criterion is in frequency domain.
(A) 2,3 and 4 are correct (B) 1,2 and 3 are correct (C) 3 and 4 are correct (D) all four are correct

70. Register and counters are similar in the sense that they both
(A) count pulses (B) store binary operation (C) shift operation
(C) made from an array of flip flops and gates integrated on a single chip.

71. InD/A converter, the resolution required is 50mv and the total maximum input is 10v. The number of bits required is
(A) 7 (B) 8 (C) 9 (D) 200

72. On different unit impulse function results in
(A) Unit parabolic function (B) Unit triplet (C) Unit doublet (D) Unit ramp function

73. ……….. watt of power is received from sun per m2 surface area of a geosynchronous satellite
(A) 100 (B) 500 (C) 2000 (D) 1000

74. The ripple factor in an LC filter.
(A) Increases with the load current (B) Increases with the load resistance
(C) Remains constant with the load current (D) Has the lowest value

75. In different parts of the country identical telephone numbers are distinguished by their
(A) Language digits (B) Access digits (C) Area codes (D) Central office codes

76.Amplitude modulation is used for broadcasting because
(A) it is move noise immune than other modulation systems
(B) compared with other systems it requires less transmitting power
(C) its use avoids receiver complexity
(D) no other modulation system can provide the necessary bandwidth for high fidelity.

77. The maximum phase shift that can be provided by a lead compensator with transfer function.
1+6S
G0(S) =______
1+2S
(A) 15o
(B) 45o
(C) 30o
(D) 60o

78. The correct sequence of steps required to improve system stability is
(A) Insertderivative action, use negative feedback, reduce gain (B) Reduce gain, use negative feedback, insert derivative action (C) Reduce gain, insert derivative action, use negative feedback (D) Use negative feedback, reduce gain, insert derivative action,

79. Identity slope change at? = 10 of the magnitudev/s frequency characteristic of a unity feedback system with the following open-loop transfer function.
A -80 dB/dec to -60 dB/dec
B 40 dB/dec to 20 dB/dec
C 20 dB/dec to -40 dB/dec
D 40 dB/dec to -20 dB/dec

80. In the feedback control system the loop transfer function is given by K
G(s)H(s)=_____________
S(s+2)(s2+2s+2) Number of asymptotes of its root loci is
A. 1 B. 2
C. 3
D. 4

81. In a closed – loop transfer function
G(s)
2600 k(s+25)
____= _____________________________
H(s)
s4+125s3+5100s2+65000s+65000 k
A. ±j228 B. ±j2.28 C. ±j1.14 D. j114

82. Considering the following statement : In a magic tee
1. the collinear arms are isolated from each other
2. one of the collinear is isolated from the E-arm
3. one of the collinear arm is isolated from the H-arm
4. E-arm and H-arm are isolated from each other. Of these statements
(A) 1 and 2 are correct (B) 1 and 3 are correct (C) 1 and 4 are correct (D) 2 and 3 are correct.

83. In 1965 first geostationary satellite was launched called
(A) ANIK (B) EARLY BIRD (Intel sat – 1) (C) WESTAR (D)MOLNIYA

84. When A = 0., B = 0, C = 1 then in two input logic gate we get gate
(A) XOR gate (B) AND gate (C) NAND gate (D) NOR gate

(A) is tuned above the stations incoming frequency (B) amplifies the output of local oscillator
(C) is fixed tuned to one particular frequency (D) can be tuned to various isolate frequencies

86. A duplexer is used to
(A) Couple two antennas to a transmitter without interference
(B) isolate the antenna from the local oscillator
(C) prevent interference between two antennas connected to a receiver
(D) use an antenna for reception or transmission without interference.

87. Boolean algebra is based on
(A) numbers (B) logic (C) truth (D) symbols

88. The amplifiers following the modulated stage in a low level modulation AM system be
(A) linear amplifier (B) harmonic generators (C) class C power amplifiers (D) class untuned amplifiers

89. In a radar system maximum unambiguous range depends on
(A) maximum power of the transmitter (B) pulse repetition frequency
(C) width of the transmitted pulse (D) sensitivity of the radar receiver.

90. In composite video waveform the function of the serrations, is to
(A) equalize the charge in the integrator before the start of vertical retrace
(B) help vertical synchronization (D) simplify the generation of the vertical sync pulse

91. The frequency range 30MHz – 300MHz is
(A) medium frequency (B) very high frequency (C) super high frequency (D) Infrared frequency

92. Which wave cannot exist inside wave guide
(A) TE (B) TM (C) TEM (D) HE

93.Ionosphere layer of earth is situated at
(A) upto 18 kms from earth (B) from 18 to 70 km (C) 70 to 500 km (D) above 500km

94. A two cavity klystron tube is a
(A) velocity modulated tube (B) frequency modulated tube
(C) Amplitude modulated tube (D) simple triode

95. As the thermal noise get doubled due to the increase in a resistance the noise power get.
(A) doubled (B) quadruped (C) unchanged (D) halved.

96.Which one is a cross field tube
(A) Klystron (B) Reflex Klystron (C) Magnetron (D) TWT

97. The degree of coupling depends
(A) size of hole (B) location of holes (C) size and location of holes (D) not depend on size or location of hole

98. The thermal noise depends on
(A) direct current through device
(B) resistive component of resistance
(C) reactive component of impedance

99. The charge on a hole is
(A) 1.6 x 10-9
(B) 1.6 x 10-19
(C) 1.6 x 101
(D) 1.6 x 1020

100. Intel’s 8085 microprocessor chip contains
(A) seven 8 bit registers (B) 8 seven bits registers (C) seven 7 bit registers (D) eight 8 bit registers.

PART III

101. The words Satyameva Jayathe’ have been taken from
(A) Vedas (B) Bhagavad Gita (C) Mundaka Upanishada (D) Mahabharatha (E) None of these

102.Which of the following countries was the first to develop a neutron bomb?
(A) USA (B) USSR (C) China (D) Pakistan

103. “Kathakali” dance is connected with

104. The term “Ashes” is associated with
(A) Hockey (B) Cricket (C) Soccer (D) None of these.

105. The Kailash Temple at Ellora is a specimen of
(A) Guptaarchit ecture (B) Rashtrakutlas architecture (C) Chalukya architecture (D) Chola architecture

106. When the two Houses of Parliament differ regarding a Bill then the controversy is solved by
(A) Joint sitting of the two Houses
(B) President of India
(C) Prime Minister of India
(D) BY a special committee for the purpose

107. Which of the following is not work of kalidasa?
(A) Meghdood (B) Reghuvansha (C) Sariputra Prakarma (D) Ritushamhara

108. Amir Khusro was the famous poet and aesthete of
(A) Akbar the Grest (B) Mahmud Ghaznvi (C) Snah Jahan (D) Alauddin Khilji

109. With the beginings of spacetrav el, we entered a new
(A) Era of great history (B) List (C) Book (D) Year

110. An though it mourns the death of someone, need not be sad.
(A) Funny poem (B) Newspaper article (C) Othodox talk (D) Elegy

111. If stare is glance so gulp is
(A) Sip (B) Tell (C) Salk (D) Admire

112. He hardly works means
(A) The work is hard (B) He is hard (C) The work is easy (D) He work very little.

113. Give the opposite word for pulchritude
(A) antipathy (B) unsightliness (C) inexperience (D) languor

114. Nanometre is………………….. part of metre
(A) MIllionth (B) Ten Millionth (C) Billionth (D) Ten billionth

115. Malaria affects
(A) Liver (B) Spleen (C) Intestine (D) Lungs

116. Sindhu Rakshak is a /an
A) Aircraft carrier (B) Submarine (C) Multiple purpose fighter (D) Anti-aircraft gun

117. With which subject is ” Dada Saheb Phalke Award” associated.
(A) Best film director
(B) Best musician
(C) Best documentary
(D) Best work relating to promotion of Indian film industry

118. Who developed the branch of mathematics known as Calculus?
(A) Arybhatta (B) Newton (C) Einstein (D) Archimedes

119. In which state in Kanha Part situated?
(A) M.P (B) U.P (C) Assam (D) W.Bengal

120. Which day is observed as Human Rights Day?
(A) 24th October (B) 4th July (C) 8th Auguest (D) 10th December

1. (C) 2. (B) 3. (C) 4. (C) 5. (C) 6. (C) 7. (B) 8.(D) 9. (A) 10. (B) 11. (B) 12.(B) 13. (B) 14. (B) 15. (C) 16.(A) 17. (C) 18. (C) 19. (C) 20. (C) 21. (C) 22. (B) 23. (D) 24. (D) 25.(B) 26.(B) 27.(A) 28.(A) 29. (B) 30.(A) 31. (C) 32. (B) 33.(D) 34. (C) 35. (B) 36. (C) 37. (D) 38. (A) 39(C) 40.(C) 41. (A) 42. (B) 43.(C) 44. (C) 45.(C) 46.(B) 47. (C) 48. (C) 49. (C) 50. (B) 51. (A) 52. (B) 53. (C) 54. (C) 55. (C) 56. (B) 57. (D) 58. (A) 59. (B) 60. (D) 61.(A) 62. (A) 63. (D) 64. (B) 65. (D) 66. (D) 67. (C) 68. (D) 69 (D) 70. (D) 71. (B) 72. (C) 73. (D) 74 (D) 75. (C) 76. (C) 77.(C) 78. (D) 79. (A) 80. (D) 81. (A) 82. (C) 83. (C) 84. (C) 85. (C) 86. (C) 87. (B) 88. (C) 89.(B) 90. (C) 91.(B) 92. (C) 93. (C) 94. (A) 95. (C) 96. (C) 97. (B) 98. (B) 99. (B) 100. (A) 101. (A) 102. (A) 103. (A) 104. (B) 105. (D) 106. (C) 107. (D) 108. (A) 109. (A) 110. (D) 111. (A) 112. (D) 113. (B) 114. (B) 115. (B) 116. (D) 117. (C) 118. (C) 119. (B) 120. (A).

Whole-Testpaper
1. In a class composed of x girls and y boys what part of the class is composed of girls
A.y/(x + y)
B.x/xy
C.x/(x + y)
D.y/xy
Ans.C

2. What is the maximum number of half-pint bottles of cream that can be filled with a 4-gallon can of cream(2 pt.=1 qt. and 4 qt.=1 gal)
A.16
B.24
C.30
D.64
Ans.D

3. If the operation,^ is defined by the equation x ^ y = 2x + y,what is the value of a in 2 ^ a = a ^ 3
A.0
B.1
C.-1
D.4
Ans.B

4. A coffee shop blends 2 kinds of coffee,putting in 2 parts of a 33p. a gm. grade to 1 part of a 24p. a gm.If the mixture is changed to 1 part of the 33p. a gm. to 2 parts of the less expensive grade,how much will the shop save in blending 100 gms.
A.Rs.90
B.Rs.1.00
C.Rs.3.00
D.Rs.8.00
Ans.C

5. There are 200 questions on a 3 hr examination.Among these questions are 50 mathematics problems.It is suggested that twice as much time be spent on each maths problem as for each other question.How many minutes should be spent on mathematics problems
A.36
B.72
C.60
D.100
Ans.B

6. In a group of 15,7 have studied Latin, 8 have studied Greek, and 3 have not studied either.How many of these studied both Latin and Greek
A.0
B.3
C.4
D.5
Ans.B

7. If 13 = 13w/(1-w) ,then (2w)2 =
A.1/4
B.1/2
C.1
D.2
Ans.C

8. If a and b are positive integers and (a-b)/3.5 = 4/7, then
(A) b < a
(B) b > a
(C) b = a
(D) b >= a
Ans. A

9. In june a baseball team that played 60 games had won 30% of its game played. After a phenomenal winning streak this team raised its average to 50% .How many games must the team have won in a row to attain this average?
A. 12
B. 20
C. 24
D. 30
Ans. C

10. M men agree to purchase a gift for Rs. D. If three men drop out how much more will each have to contribute towards the purchase of the gift/
A. D/(M-3)
B. MD/3
C. M/(D-3)
D. 3D/(M2-3M)
Ans. D

11. A company contracts to paint 3 houses. Mr.Brown can paint a house in 6 days while Mr.Black would take 8 days and Mr.Blue 12 days. After 8 days Mr.Brown goes on vacation and Mr. Black begins to work for a period of 6 days. How many days will it take Mr.Blue to complete the contract?
A. 7
B. 8
C. 11
D. 12
Ans.C

12. 2 hours after a freight train leaves Delhi a passenger train leaves the same station travelling in the same direction at an average speed of 16 km/hr. After travelling 4 hrs the passenger train overtakes the freight train. The average speed of the freight train was?
A. 30
B. 40
C.58
D. 60
Ans. B

13. If 9x-3y=12 and 3x-5y=7 then 6x-2y = ?
A.-5
B. 4
C. 2
D. 8
Ans. D

ANALYTICAL ABILITY
1. The office staff of XYZ corporation presently consists of three bookeepers–A, B, C and 5 secretaries D, E, F, G, H. The management is planning to open a new office in another city using 2 bookeepers and 3 secretaries of the present staff . To do so they plan to seperate certain individuals who don’t function well together. The following guidelines were established to set up the new office.
I. Bookeepers A and C are constantly finding fault with one another and should not be sent together to the new office as a team
II. C and E function well alone but not as a team , they should be seperated
III. D and G have not been on speaking terms and shouldn’t go together
IV Since D and F have been competing for promotion they shouldn’t be a team.

1.If A is to be moved as one of the bookeepers,which of the following cannot be a possible working unit.
A.ABDEH
B.ABDGH
C.ABEFH
D.ABEGH
Ans.B

2.If C and F are moved to the new office,how many combinations are possible
A.1
B.2
C.3
D.4
Ans.A

3.If C is sent to the new office,which member of the staff cannot go with C
A.B
B.D
C.F
D.G
Ans.B

4.Under the guidelines developed,which of the following must go to the new office
A.B
B.D
C.E
D.G
Ans.A

5.If D goes to the new office,which of the following is/are true
I.C cannot go
II.A cannot go
III.H must also go
A.I only
B.II only
C.I and II only
D.I and III only
Ans.D 2.
2.After months of talent searching for an administrative assistant to the president of the college the field of applicants has been narrowed down to 5–A, B, C, D, E .It was announced that the finalist would be chosen after a series of all-day group personal interviews were held.The examining committee agreed upon the following procedure
I.The interviews will be held once a week
II.3 candidates will appear at any all-day interview session
III.Each candidate will appear at least once
IV.If it becomes necessary to call applicants for additonal interviews, no more 1 such applicant should be asked to appear the next week
V.Because of a detail in the written applications,it was agreed that whenever candidate B appears, A should also be present.
VI.Because of travel difficulties it was agreed that C will appear for only 1 interview.
1.At the first interview the following candidates appear A,B,D.Which of the follwing combinations can be called for the interview to be held next week.
A.BCD
B.CDE
C.ABE
D.ABC
Ans.B
2.Which of the following is a possible sequence of combinations for interviews in 2 successive weeks
A.ABC;BDE
B.ABD;ABE
D.BDE;ACD
Ans.C
3.If A ,B and D appear for the interview and D is called for additional interview the following week,which 2 candidates may be asked to appear with D?
I. A
II B
III.C
IV.E
A.I and II
B.I and III only
C.II and III only
D.III and IV only
Ans.D
4.Which of the following correctly state(s) the procedure followed by the search committee
I.After the second interview all applicants have appeared at least once
II.The committee sees each applicant a second time
III.If a third session,it is possible for all applicants to appear at least twice
A.I only
B.II only
C.III only
D.Both I and II
Ans.A 3. A certain city is served by subway lines A,B and C and numbers 1,2 and 3.
When it snows , morning service on B is delayed
When it rains or snows , service on A, 2 and 3 are delayed both in the morning and afternoon
When temp. falls below 30 degrees farenheit afternoon service is cancelled in either the A line or the 3 line,
but not both.
When the temperature rises over 90 degrees farenheit, the afternoon service is cancelled in either the line C or the
3 line but not both.When the service on the A line is delayed or cancelled, service on the C line which connects the A line, is delayed.When service on the 3 line is cancelled, service on the B line which connects the 3 line is delayed.
1. On Jan 10th, with the temperature at 15 degree farenheit, it snows all day. On how many lines will service be
affected, including both morning and afternoon.
(A) 2
(B) 3
(C) 4
(D) 5
Ans. D
2. On Aug 15th with the temperature at 97 degrees farenheit it begins to rain at 1 PM. What is the minimum number
of lines on which service will be affected?
(A) 2
(B) 3
(C) 4
(D) 5
Ans. C
3. On which of the following occasions would service be on the greatest number of lines disrupted.
(A) A snowy afternoon with the temperature at 45 degree farenheit
(B) A snowy morning with the temperature at 45 degree farenheit
(C) A rainy afternoon with the temperature at 45 degree farenheit
(D) A rainy afternoon with the temperature at 95 degree farenheit
Ans. B 4. In a certain society, there are two marriage groups, red and brown. No marriage is permitted within a group. On marriage, males become part of their wives groups; women remain in their own group. Children belong to the same group as their parents. Widowers and divorced males revert to the group of their birth. Marriage to more than one person at the same time and marriage to a direct descendant are forbidden
1. A brown female could have had
I. A grandfather born Red
II. A grandmother born Red
III Two grandfathers born Brown
(A) I only
(B) III only
(C) I, II and III
(D) I and II only
Ans. D
2. A male born into the brown group may have
(A) An uncle in either group
(B) A brown daughter
(C) A brown son
(D) A son-in-law born into red group
Ans. A
3. Which of the following is not permitted under the rules as stated.
(A) A brown male marrying his father’s sister
(B) A red female marrying her mother’s brother
(C) A widower marrying his wife’s sister
(D) A widow marrying her divorced daughter’s ex-husband
Ans. B
4. If widowers and divorced males retained their group they had upon marrying which of the following would be permissible ( Assume that no previous marriage occurred)
(A) A woman marrying her dead sister’s husband
(B) A woman marrying her divorced daughter’s ex-husband
(C) A widower marrying his brother’s daughter
(D) A woman marrying her mother’s brother who is a widower.
Ans. D
5. I. All G’s are H’s
II. All G’s are J’s or K’s
III All J’s and K’s are G’s
IV All L’s are K’s
V All N’s are M’s
VI No M’s are G’s
Q1. If no P’s are K’s which of the following must be true
(A) No P is a G
(B) No P is an H
(C) If any P is an H it is a G
(D) If any P is a G it is a J
Ans. D
2. Which of the following can be logically deduced from the stated conditions
(A) No M’s are H’s
(B) No H’s are M’s
(C) Some M’s are H’s
(D) No N’s are G’s
Ans. D
3. Which of the following is inconsistent with one or more conditions
(A) All H’s are G’s
(B) All H’s are M’s
(C) Some H’s are both M’s and G’s
(D) No M’s are H’s
Ans. C
4. The statement “No L’s are J’s” is
I. Logically deducible from the conditions stated
II Consistent with but not deducible from the conditions stated
III. Deducible from the stated conditions together with the additional statements “No J’s are K’s”
(A) I only
(B) II only
(C) III only
(D) II and III only
Ans. D
Technical 1. What is meant by polymorphism
Ans. Redfinition of a base class method in a derived class
2. What is the essential feature of inheritance
Ans. All properties of existing class are derived.
3. What does the protocol FTP do
Ans. Transfer a file b/w stations with user authentification
4. In the transport layer ,TCP is what type of protocol
Ans. Connection oriented.
5. Why is a gateway used
Ans. To connect incompatible networks.
6. How is linked list implemented
Ans. By referential structures.
7. What method is used in Win95 in multitasking?
Ans. Non preemptive check.
8. What is meant by functional dependency?
9. What is a semaphore?
Ans. A method synchronization of multiple processes
10. What is the precedence order from high to low ,of the symbols ( ) ++ /
Ans.( ) , ++, /
11. Preorder of A*(B+C)/D-G
Ans.*+ABC/-DG 12. B-tree (failure nodes at same level)
13. Dense index (index record appers for every search -key in file)
14. What is the efficiency of merge sort
Ans. O(n log n)
15. A program on swaping ( 10,5 )was given
16. In which layer are routers used
17. Ans.In network layer
18. In which layer are packets formed ( in network layer )
19. heap ( priority queue )
20. Copy constructor ( constant reference )
21. 26.Which of the following sorting algorithem has average sorting behavior
–Bubble sort,merge sort,heap sort,exchange sort
Ans. Heap sort
22. In binary search tree which traversal is used for getting ascending order values–Inorder ,post order,preorder
Ans.Inorder
23. What are device drivers used for
Ans.To provide software for enabling the hardware
24. Irrevalent to unix command ( getty)
25. What is fork command in unix
Ans. System call used to create process
26. What is make command in unix
Ans. Used forcreation of more than one file
27. In unix .profile contains
Ans. Start up program
28. In unix echo is used for ( answer C)
29. In unix ‘ls ‘stores contents in
Ans.inode block

BSNL DGM previous years solved question papers
BSNLDGM model questions with answers and detailed explanations

BSNL DGM MODEL PAPER- PART-A,BSNL DGM model questions for practice upcoming DGM examination, BSNL DGM solved question papers includes technical questions,general ability questions,and basic engineering questions. Preparation of BSNL upcoming wrritten test examination practice more model to improve your knowledge and speed,time management for exam.

BSNL DGM Objective questions
1. First-level managers must possess skills, which include knowledge of and proficiency in the methods, processes and procedures for carrying out activities.
a. Human
b. Conceptual
c. Design
d. Technical

2. Which of the following skills is important at all levels of an organization?
a. Conceptual
b. Design
c. Human
d. Technical

3. Which of the following skills indicates the ability to solve problems in ways that will benefit the enterprise?
a. Design
b. Human
c. Conceptual
d. Technical

4. Managers possessing skill have the ability to understand and coordinate the full range of corporate objectives and activities.
a. Design skill
b. Human skill
c. Conceptual skill
d. Technical skill

5. Which of the following approaches to management examines practical cases but is having only limited value for developing management theory?
a. Group behavior approach
b. Systems approach
c. Operational approach
d. Empirical approach

6. Which of the following is also known as the mathematical approach?
a. Operational approach
b. Management science approach
c. Management roles approach
d. Systems approach

7. Which of the following approaches to management advocates a system ofcooperation using both interpersonal and group behavioral aspects?
a. Sociotechnical approach
b. Contingency approach
c. Situational approach
d. Cooperative social systems approach

8. Under which system does a worker’s wage increase in proportion to theoutput produced?
a. Time-and-motion study
b. Piece-rate incentive system
c. Micromotion study
d. Gantt Chart

9. Who proposed the task-and-bonus system under which workers are given a bonus if the work is completed before the set time?
a. Frederick W. Taylor
b. Henry L. Gantt
c. Frank B. Gilbreth
d. Max Weber

10. The theorists ignored the human desire for job satisfaction.
a. Scientific management
b. Bureaucratic management
d. Management science

11. Which type of management approach focuses only on the economic andphysical needs of workers and ignores their social needs?
a. Scientific management
b. Bureaucratic management
d. Operations management

12.Which one of the following did not contribute to the behavioral concept ofmanagement?
a. Elton Mayo
b. Mary Parker Follet
c. Chris Argyris
d. Henry R. Towne

13. A branch of the classical viewpoint of management, is basedon Max Weber’s research in the field of management.
a. Bureaucratic management
b. Scientific management
d. Weber management
14. which of the following is the fastest memory in the terms of accessibility?
2. Cache memory
3.Random Access memory
4. Dynamic random access Memory

15. Registers are associated with_________
1. Input
2. memory
3.control
4. output

16. _______________ is an example of sequential storage device
1. Magnetic Tape
2. floppy disk
3. Hard disk
4. CD-ROM

17.Programs and procedures in an information system are _____________
1. data resources
2. people resources
3. hardware and software resources
4. all the above

18.The information circulated in a company grapevine can be called as ____________
1. knowledge information
2. sampled information
3.informal information
4. organizational information

19.what is the term used to refer to alignment of the beginning and end of lines
1.indentation
2. justification
3. superscript
4 font

20. what is the character positioned below normal text called?
1. superscript
2. italic
3.font
4.subscript

21. spread sheet is a ________________
1. superscript
2.Italic
3.font
4.subscript

22.The first Factories Act was enacted in
a),1881
b),1895
c),1897
d),1885

23, Who is an adult as per Factories Act, 1948 ?
a. Who has completed 18 years of age
b. who is less than 18 years
c. who is more than 14 years
d. who is more than 15 years
Answer- a). Who has completed 18 years of age

24. A person who has ultimate control over the affairs of the factory under Factories Act, 1948 is called as _________

a. Occupier
b. Manager
c. Chairman
d. Managing Director.

25, The space for every worker employed in the Factory after the commencement of Factories Act, 1948 should be ________ Cubic Meters.

a. 9.9
b. 10.2
c. 14.2
d. 13.2
26,The provision for cooling water during hot weather should be made by the organization if it employees _______ or more employees.

a. 200
b. 250
c. 300
d. 150

27.Who is an Adolescent as per Factories Act, 1948 ?
a. Who has completed 17 years of age
b. who is less than 18 years
c. who has completed 15 years but less than 18 years.
d. None of these
Answer- c. who has completed 15 years but less than 18 years.

28, Which one of the following is not a welfare provision under Factories Act, 1948
a.Canteen
b. Creches
c.First Aid
d.Drinking water.

29, First Aid Boxes is to be provided for ______ of persons
a. 125
b. 135
c. 150
d. 160

30,Safety Officers are to be appointed if Organisation is engaging ______ or more employees.
a. 1000
b. 2000
c. 500
d. 750

31 Canteen is to be provided if engaging employees more than ______ persons.
a. 250
b. 230
c. 300
d. 275

32 Leave with wages is allowed for employees if they work for _______ days in a month.
a. 15
b. 25
c. 20
d. 28

33. Welfare Officers are to be appointed if Organisation is engaging ______ or more employees.
a. 500
b. 250
c. 600
d. 750

34. The Ambulance Room is to be provided if engaging employees more than______
a. 400
b. 350
c. 500
d. 450

35, Creche is to be provided if ______ or more lady employees are engaged.
a. 25
b. 32
c. 30
d. 40

36. An adult worker can upto ____ hrs in a day as per factories Act, 1948
a. 8
b. 9
c. 10
d. 12

37, Obligations of Workers under the Factories Act 1947 was discussed in section —–
a) 78
b) 101
c) 111
d) 99

38. The term Sabbatical is connected with
a) Paid leave for study
b) Paternity leave
c) Maternity leave
d) Quarantine leave

39. Section 49 of the Factories Act 1947 Says about
a) Welfare officer
b) Canteen
c) Rest room
d) Crèche

40. Section 2 ( K )of the Factories Act 1947 says about
a) Manufacturing Process
b) Factory
c) Worker
d) None of these

41., If the factory employs more than 1000 workers, they should appoint qualified ————- to carry out the prescribed duties
a) Safety Officer
b) Welfare officer
c) Security officer
d) None of these

42. For contravention of provisions of Factories Act or Rules, the occupier shall liable for punishment up to
a)2 years or fine up to Rs.1,00,000 or both
b) 6 months or fine upto 10, 000 or both
c) 3 three years or fine 10, 000 or both
d) None of these
Answer –a)2 years or fine up to Rs.1,00,000 or both.

43. In case of fatal accident occurred inside the factory , a separate accident report shall be sent to the District magistrate in Form No —- within 12 hours
a) Form No:16
b) Form No:18 A
c) Form No :18 B
d) Form No:18

44., Manager of every factory should sent a annual report to the Inspectorate of factories containing details like numbers of workers employed , leave with wages, safety officers ,ambulance room, canteen, shelter, accidents in form no — on or before 31 st January
a) Form No : 22
b) Form No: 21
c) Form No: 25 A
d) Form No: 25 B

45. If any employee found violating the section 20 of Factories Act 1947 shall be fine up to
a)Rs. 10
b) Rs. 5
c) Rs. 15
d) Rs.20

46. Section 41- G of the Factories Act 1948 says about
a) Fencing of machineries
b) Facing of machineries
c) Work on near machinery in motion
Answer-d) Workers participation in safety management

47. Find the minimum value of the objective function where minimum z=20x+35y
1. 2100
2.1600
3.800
4.3700

48. which of the following is not an advantage of MRP system?
1. Ability to price competitively
2. Better Customer service
3. longer idle time
4. Reduced set up and tear –down costs

49. Accounting Ratios are important tools used by
(a) Managers,
(b) Researchers,
(c)Investors,
(d) All of the above

50. Net Profit Ratio Signifies:
(a) Operational Profitability,
(b) Liquidity Position,
(c) Big-term Solvency,
(d)Profit for Lenders.

51. Working Capital Turnover measures the relationship of Working Capital with:
(a)Fixed Assets,
(b)Sales,
(c)Purchases,
(d)Stock.

52.. In Ratio Analysis, the term Capital Employed refers to:
(a)Equity Share Capital,
(b)Net worth,
(c)Shareholders’ Funds,
(d)None of the above.

53. Dividend Payout Ratio is:
(a)PAT Capital,
(b)DPS ÷ EPS,
(c) Pref. Dividend ÷ PAT,
(d) Pref. Dividend ÷ Equity Dividend.

54 DU PONT Analysis deals with:
(a) Analysis of Current Assets,
(b)Analysis of Profit,
(c)Capital Budgeting,
(d) Analysis of Fixed Assets

55. In Net Profit Ratio, the denominator is:
(a)Net Purchases,
(b)Net Sales,
(c) Credit Sales,
(d) Cost of goods sold.

56. Inventory Turnover measures the relationship of inven¬tory with:
(a) Average Sales,
(b)Cost of Goods Sold,
(c)Total Purchases,
(d) Total Assets.

57.. The term ‘EVA’ is used for:
(a)Extra Value Analysis,
,(c)Expected Value Analysis,
(d)Engineering Value Analysis.

58.. Return on Investment may be improved by:
(a)Increasing Turnover,
(b) Reducing Expenses,
(c)Increasing Capital Utilization,
(d)All of the above.

59.. In Current Ratio, Current Assets are compared with:
(a)Current Profit,
(b)Current Liabilities,
(c)Fixed Assets,
(d)Equity Share Capital.

60.. ABC Ltd. has a Current Ratio of 1.5: 1 and Net Current Assets of Rs. 5,00,000. What are the Current Assets?
(a)Rs. 5,00,000,
(b)Rs. 10,00,000,
(c)Rs. 15,00,000,
(d) Rs. 25,00,000

61. There is deterioration in the management of working capital of XYZ Ltd. What does it refer to?
(a)That the Capital Employed has reduced,
(b)That the Profitability has gone up,
(c)That debtors collection period has increased,
(d)That Sales has decreased.

62. Which of the following does not help to increase Current Ratio?
(a)Issue of Debentures to buy Stock,
(b)Issue of Debentures to pay Creditors,
(c)Sale of Investment to pay Creditors,
(d)Avail Bank Overdraft to buy Machine.

63. Debt to Total Assets Ratio can be improved by:
(a)Borrowing More,
(b)Issue of Debentures,
(c)Issue of Equity Shares,
(d)Redemption of Debt.

64.. Ratio of Net Income to Number of Equity Shares known as:
(a)Price Earnings Ratio,
(b) Net Profit Ratio,
(c)Earnings per Share,
(d) Dividend per Share.

65. Trend Analysis helps comparing performance of a firm
(a)With other firms,
(b)Over a period of firm,
(c)With other industries,
(d) None of the above.

66. A Current Ratio of Less than One means:
(a)Current Liabilities < Current Assets,
(b)Fixed Assets > Current Assets,
(c)Current Assets < Current Liabilities,
(d) Share Capital > Current Assets.

67. XYZ Ltd. has earned 8% Return on Total Assests of Rs. 50,00,000 and has a Net Profit Ratio of 5%. Find out the Sales of the firm.
(a) Rs. 4,00,000,
(b)Rs. 2,50,000,
(c)Rs. 80,00,000,
(d)Rs. 83,33,333.

68. Suppliers and Creditors of a firm are interested in
(a)Profitability Position,
(b)Liquidity Position,
(c)Market Share Position,
(d) Debt Position.

69. Which of the following is a measure of Debt Service capacity of a firm?
(a)Current Ratio,
(b)Acid Test Ratio,
(c) Interest Coverage Ratio,
(d) Debtors Turnover.

70. Gross Profit Ratio for a firm remains same but the Net Profit Ratio is decreasing. The reason for such behavior could be:
(a) Increase in Costs of Goods Sold,
(b)If Increase in Expense,
(c) Increase in Dividend,
(d)Decrease in Sales.

71. Which of the following statements is correct?
(a) A Higher Receivable Turnover is not desirable,
(b) Interest Coverage Ratio depends upon Tax Rate,
(c)Increase in Net Profit Ratio means increase in Sales,
(d) Lower Debt-Equity Ratio means lower Financial Risk.

72. Debt to Total Assets of a firm is .2. The Debt to Equity boo would be:
(a) 0.80,
(b)0.25,
(c) 1.00,
(d)0.75

(a) Return on Assets,
(b) Earnings Per Share,
(c) Net Profit Ratio,
(d)Return on Investment.

74. Return on Assets and Return on Investment Ratios be¬long to:
(a) Liquidity Ratios,
(b)Profitability Ratios,
(c)Solvency Ratios,
(d)Turnover.

75. XYZ Ltd. has a Debt Equity Ratio of 1.5 as compared to 1.3 Industry average. It means that the firm has:
(a) Higher Liquidity,
(b)Higher Financial Risk,
(c)Higher Profitability,
(d)Higher Capital Employed.
————————————– END OF PART-A ————————————-

BSNL previous years solved sample placement papers,BSNL DGM,JTO Tech Assistant questions with answers,BSNL model questions for practicce,BSNL technical assistant question papers wit answers and detalied explnations

1. Weins bridge is used for measurement of frequency in the applied voltage waveform is measurement of frequency in the applied voltage waveform is
(a) Sinusoidal (Ans)
(b) Square
(c) rectangular
(d) triangular

2. Strain gauge is
(a) not a transducer
(b) an active transducer (Ans)
(c) not an electronic
(d) none

3. A high Q coil has
(a) large band width
(b) high losses (Ans)
(c) low losses
(d) flat response

4. In the case of an instrument reading of 8.3V with a 0 to 150 voltmeter having a guaranteed accuracy of 1% full scale reading, the percentage limiting error is
(a) 1.810 %
(b) 0.181 %
(c) 12.45 % (Ans)
(d) 0.0018%
(Explanation : Limiting error at full scale = 1/100 X 150 = 1.5 volt
the true reading may be (8.3 + 1.5) Volt the relative error = 1.5/100 X 8.3 = 12.45 % )

5. The ‘h’ parameter equivalent circuit of a junction transistor is valid for
(a) High frequency, large signal operation
(b) High frequency, small signal operation
(c) Low frequency, small signal operation (Ans)
(d) Low frequency, large signal operation

6. A system is casual if the output of any time depends only on
(a) Values of input in the past and in the future
(b) Values of input at that time and in the past (Ans)
(c) Values of input at that time and in the future
(d) None

7. From the hot metal surface electrons escape because
(a) of change of state from metal to gas due to heat
(b) of change of state from gas to metal
(c) the energy greater than the work function (Ans)
(d) the energy is greater than Fermi level

8. The most common device used for detection in radio receivers is
(a) amplifier
(b) triode
(c) diode (Ans)
(d) transistor

9. In a full wave rectifier the negative point in a circuit is
(a) Cathode
(b) anode
(c) The central tap on the high voltage secondary (Ans)
(d) Plate

10. Negative feedback amplifier has a signal corrupted by noise as its input
(a) Amplify the noise as much as the signal
(b) Reduce the noise (Ans)
(c) Increase the noise
(d) Not effect the noise

PART II
11. It is an unidirectional device that blocks the current flow from cathode to anode
(a) SCR (Ans)
(b) PCR
(c) VCR
(d) DCR

12. An ideal constant current source is connected in series with an ideal constant voltage source. Considering together the combination will be a
(a) constant voltage source
(b) constant current source (Ans)
(c) constant voltage and a constant current source or a constant power source
(d) resistance

13. A node current in an thyristor is made up of
(a) electrons only
(b) electrons or holes
(c) electrons and holes (Ans)
(d) holes only

14. For a pulse transformer, the material used for its core and the possible turn ratio from primary to secondary are respectively
(a) ferrite : 20:1
(b) laminated iron : 1:1
(c) ferrite : 1:1 (Ans)
(d) powdered iron :1:1

15. A converter which can operate in both 3 pulse and 6 pulse modes is a
(a) 1 phase full converter
(b) 3 phase half wave converter
(c) 3 phase semi converter (Ans)
(d) 3 phase full converter

16. A single phase CSI has capacitor C as the load. For a constant source current, the voltage across the capacitor is
(a) square wave
(b) triangular wave (Ans)
(c) step function
(d) pulsed wave

17. A single phase full wave midpoint thyristor convertor uses a 230/200 V transformer with centre tap on the secondary side. The P.I.V per thyristor is
(a) 100 V
(b) 141.4V
(c) 200 V
(d) 282.8 V (Ans)
(Explanation : For centre taped transformer in output side the PIV = 2 Vrms = 2 x 200/v2 = 282.8 Volt)

18. In dc choppers for chopping period T, the output voltage can be controlled by FM by varying
(a) T keeping Ton constant (Ans)
(b) Ton keeping T constant
(c) Toff keeping T constant
(d) None of the above

19. An ideal power supply consist of
(a) A Very small output resistance
(b) Zero internal resistance (Ans)
(c) Very large input resistance
(d) Very large output resistance

20. The linearity error for a digital input is indicated by
(a) ?
(b) y
(c) ?
(d) e (Ans)

21. In the 8421 BCD code the decimal number 125 is written as
(a) 1111101 (Ans)
(b) 0001 0010 0101
(c) 7D
(d) None of the above
Explanation :

22. Match the given feedback circuit with its proper nomenclatures

(a) Current series feedback (Ans)
(b) Current shunt feedback
(c) Voltage series feedback
(d) Voltage shunt feedback

23. Class A amplifier is used when
(a) No phase inversion is required
(b) Highest voltage gain is required
(c) dc voltages are to be amplified
(d) Minimum distortion is desired (Ans)

24. Identify the correct match for the give transistor

(a) Enhancement type P channel MOSFET
(b) Depletion type N channel MOSFET (Ans)
(c) Enhancement type N channel MOSFET
(d) Depletion type P channel MOSFET

25. In case a signal band limited to fermimeter is sampled at a rate less than 2 fermimeter , the constructed signal will be
(a) Distortionless
(b) Small in amplitude
(c) Having higher frequencies suppressed
(d) Distorted (Ans)

26. IC which has quad 2 input AND gates
(a) 7411
(b) 7404
(c) 7400
(d) 7408 (Ans)

27. Registers in which data is entered or taken out in serial form are referred as
(a) left shift register
(b) right shift register
(c) shift registers (Ans)
(d) none of the above

28. The expression ABC can be simplified to
(a) A B C
(b) AB + BC + CA
(c) A B + C
(d) A + B + C (Ans)

(i) Routh Herwitz’s criterion is in time domain
(ii) Root locus plot is in time domain
(iii) Bode plot is in frequency domain
(iv) Nyquist criterion is in frequency domain (Ans)

(a) 2, 3 and 4 are correct
(b) 1, 2 and 3 are correct
(c) 3 and 4 are correct
(d) All four are correct

30. Register and counters are similar in the sense that they both
(a) count pulses
(b) store binary operation
(c) shift registers
(d) made from an array of flip flops and gates integrated on a single chip (Ans)

31. In D/A converter, the resolution required is 50 mv and the total maximum input is 10 V. The number of bits required is
(a) 7
(b) 8 (Ans)
(c) 9
(d) 200

32. On differentiation unit impulse function results in
(a) Unit parabolic function
(b) Unit triplet
(c) Unit doublet (Ans)
(d) Unit ramp function

33. —— watt of power is received from sun per m2 surface area of a geosynchronous satellite
(a) 100
(b) 500
(c) 2000
(d) 1000 (Ans)

34. The ripple factor in an LC filter
(a) Increase with the load current
(b) Increases with the load resistance
(c) Remains constant with the load current
(d) Has the lowest value (Ans)

35. In different parts of the country identical telephone numbers are distinguished by their
(a) Language digits
(b) Access digits
(c) Area codes (Ans)
(d) Central office codes

36. Amplitude modulation is used for broadcasting because
(a) it is move noise immune than other modulation systems
(b) compared with other systems it requires less transmitting power
(c) its use avoids receiver complexity (Ans)
(d) no other modulation system can provide the necessary bandwidth for high fidelity

37. The maximum phase shift than can be provided by a lead compensator with transfer function
G0(S) = 1 + 6S
1 + 2S
(a) 15o
(b) 45o
(c) 30o (Ans)
(d) 60o
(Explanation : If GC(s) = 1 +Tn s
1 + Td s
then Q = tan -1 ?Tn – tan-1 ?Td
Q = tan -1 6? – tan-1 2?
So maximum phase shift will be Q= 30o )

38. The correct sequence of steps required to improve system stability is
(a) Insert derivative action, use negative feedback, reduce again
(b) Reduce gain, use negative feedback, insert derivative action
(c) Reduce gain, insert derivative action, use negative feedback
(d) Use negative feedback, reduce gain, insert derivative action. (Ans)

39. Identify slope change at ?= 10 of the magnitude v/s frequency characteristic of a unity feedback system with the following open-loop transfer function
G (j?) = 5(1+j o.w)
j? (1 + j0.5?) [ (1+j 0.6 ?/50) + ( j?/50)2]
(a) -80 dB/dec to – 60 dB/dec (Ans)
(b) 40 dB/dec to 20 dB/dec
(c) 20 dB/dec to – 40 dB/dec
(d) 40 dB/dec to – 20 dB/dec
(Explanation :

Factor Corner frequency Gain and angle 5 —– 20 log5=14dB line parallel to x axis 1
j? —– -20dB/dec passing through ?=1 1
1 + j0.5? ?1=2 -20dB/dec slope originates from ?=2 1+0
(1+j 0.6 ?/50) + ( j?/50)2 ?2=7.07 -40 dB/dec slope originates from ?=7.07 1+j 0-1 ? ?3=10 +20dB/dec slope originates ?=10
40. In the feedback control system the loop transfer function is given by
G(s) H (s) = K
s(s+2) (s2 +2s +2)
Number of asymptotes of its root loci is
(a) 1
(b) 2
(c) 3
(d) 4 (Ans)

41. In a closed – loop transfer function
G (s) = 2600k(s + 25)
R (s) s4 +125s3 + 5100s2 + 65000s + 65000k
the imaginary axis intercepts of the root loci will be
(a) + j228 (Ans)
(b) +j2.28
(c) +j1.14
(d) +j114

42. Considering the following statement : In a magic tee
1. the collinear arms are isolated from each other
2. one of the collinear is isolated from the E-arm
3. one of the collinear arm is isolated from the H-arm
4. E-arm and H-arm are isolated from each other. of these statements

(a) 1 and 2 are correct
(b) 1 and 3 are correct
(c) 1 and 4 are correct (Ans)
(d) 2 and 3 are correct

43. In 1965 first geostationary satellite was launched called
(a) ANIK
(b) EARLY BIRD (Intel sat-1)
(c) WESTAR (Ans)
(d) MOLNIYA

44. When A = 0., B = 0, C=1 then in two input logic gate we get gate
(a) XOR gate
(b) AND gate
(c) NAND gate (Ans)
(d) NOR gate

(a) is tuned above the stations incoming frequency
(b) amplifies the output of local oscillator
(c) is fixed tuned to one particular frequency (Ans)
(d) can be tuned to various isolate frequencies

46. A duplexer is used to
(a) couple two antennas to a transmitter without interference
(b) isolate the antennas from the local oscillator
(c) prevent interference between two antennas connected to a receiver (Ans)
(d) use an antenna for reception or transmission without interference

47. Boolean algebra is based on
(a) numbers
(b) logic (Ans)
(c) truth
(d) symbols

48. The amplifiers following the modulated stage in a low level modulation AM system be
(a) linear amplifier
(b) harmonic generators
(c) class C power amplifiers (Ans)
(d) class B untuned amplifiers

49. In a radar system maximum unambiguous range depends on
(a) maximum power of the transmitter
(b) pulse repetition frequency (Ans)
(c) width of the transmitted pulse

50. In composite video waveform the function of the serrations, is to
(a) equalize the charge in the integrator before the start of vertical retrace.
(b) help vertical synchronization
(c) help horizontal synchronization (Ans)
(d) simplify the generation of the vertical syncpulse.

51. The frequency range 30MHz – 300 MHz is
(a) medium frequency
(b) very high frequency (Ans)
(c) super high frequency
(d) infrared frequency

52. Which wave cannot exist inside wave guide
(a) TE
(b) TM
(c) TEM (Ans)
(d) HE

53. Ionosphere layer of earth is situated at
(a) upto 18kms from each
(b) from 18 to 70 k m
(c) 70 to 500 km (Ans)
(d) above 500 km

54. A two cavity klystron tube is a
(a) velocity modulated tube (Ans)
(b) frequency modulated tube
(c) Amplitude modulated tube
(d) simple triode

55. As the thermal noise get doubled due to the increase in a resistance the noise power get
(a) doubled
(c) unchanged (Ans)
(d) halved

56. Which one is a cross field tube
(a) Klystron
(b) Reflex Klystron
(c) Magnetron (Ans)
(d) TWT

57. The degree of coupling depends on
(a) Size of hole
(b) location of holes (Ans)
(c) size and location of holes
(d) not depend on size or location of hole

58. The thermal noise depends on
(a) direct current through device
(b) resistive component of resistance (Ans)
(c) reactive component of impedance

59. The charge on a hole is
(a) 1.6 x 10-9
(b) 1.6 x 10-19 (Ans)
(c) 1.6 x 101
(d) 1.6 x 1020

60. Intel’s 8085 microprocessor chip contains
(a) seven 8 bit registers (Ans)
(b) 8 seven bits registers
(c) seven 7 bit registers
(d) eight 8 bit registers

PART -III
61. The words ‘Satyameva Jayate’ have been taken from
(a) Vedas (Ans)
(c) Mahabharata
(d) None of these

62. Which of the following countries was the first to develop a neutron bomb?
(a) USA (Ans)
(b) USSR
(c) China
(d) Pakistan

63. ‘Kathakali’ dance is connected with
(a) Kerala (Ans)
(b) Rajasthan

64. The term “Ashes” is associated with
(a) Hockey
(b) Cricket (Ans)
(c) Soccer
(d) None of these

65. The Kailash Temple at Ellora is a specimen of
(a) Gupta architecture
(b) Rashtrakutlas architecture
(c) Chalukya architecture
(d) Chola architecture (Ans)

66. When the two Houses of Parliament differ regarding a Bill then the controversy is solved by
(a) Joint sitting of the two Houses
(b) President of India
(c) Prime Minister of India (Ans)
(d) By a special committee for the purpose

67. Which of the following is not the work of Kalidasa ?
(a) Meghdoot
(b) Raghuvansha
(c) Sariputra Prakarma
(d) Ritushamhara (Ans)

68. Amir Khusro was the famous poet and aesthete of
(a) Akbar the Great (Ans)
(b) Mahmud Ghaznvi
(c) Shah Jahan
(d) Alauddin Khilji

69. With the beginnings of space travel, we entered a new
(a) Era of great history (Ans)
(b) List
(c) Book
(d) Year

70. An though it mourns the death of someone , need not be sad
(a) Funny poem
(b) Newspaper article
(c) Orthodox talk
(d) Elegy (Ans)

71. If stare is glance so gulp is
(a) Slip (Ans)
(b) Tell
(c) Salk

72. He hardly works means
(a) The work is hard
(b) He is hard
(c) The work is easy
(d) He work very little (Ans)

73. Give the opposite word for pulchritude
(a) antipathy
(b) unsightliness (Ans)
(c) inexperience
(d) languor

74. Nanometre is —–part of a metre
(a) Millionth
(b) Ten millionth (Ans)
(c) Billionth
(d) Ten billionth

75. Malaria affects
(a) Liver
(b) Spleen (Ans)
(c) Intestine
(d) Lungs

76. Sindhu Rakshak is a/an
(a) Aircraft carrier
(b) Submarine
(c) Multiple-purpose fighter
(d) Anti-aircraft gun (Ans)

77. With which subject is “Dada Saheb Phalke Award” associated ?
(a) Best film director
(b) Best musician
(c) Best documentary (Ans)
(d) Best work relating to promotion of Indian film Industry

78. Who developed the branch of mathematics know as Calculus ?
(a) Aryabhatta
(b) Newton
(c) Einstein (Ans)
(d) Archimedes

79. In which state is Kanha Park situated ?
(a) M.P.
(b) U.P. (Ans)
(c) Assam
(d) W. Bengal

80. Which day is observed as Human Rights Day ?
(a) 24th October (Ans)
(b) 4th July
(c) 8th August
(d) 10th December
Placement Paper

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BSNL OBJECTIVE TYPE QUESTIONS FOR PRACTICE

1. The electrical conductivity of metals is typically of the order of (in ohm-1 m-1)

(A) 107 (Ans)

(B) 105

(C) 10-4

(D) 10-6

2. There electronic configuration of carbon is

(A) 1s2 2s2

(B) 1s2 2s2 2p6 2s2

(C) 1s2 2s2 2p6

(D) 1s2 2s2 2p2 (Ans)

3. Which law is synonymous to the occurrence of diamagnetism?

(A) Ampere’s law

(B) Maxwell’s law

(C) Coulomb’s law

(D) Lenze’s law (Ans)

4. Which of the following are piezo-electric substances:

1. Barium titanate

(A) 1,2 and 4

(B) 1,3 and 4

(C) 1,2 and 3 (Ans)

(D) 2,3 and 4

5. The temperature below which certain materials are anti-ferromagnetic and above which they are paramagnetic is called

(A) Weiss temperature

(B) Curie temperature

(C) Neel temperature (Ans)

(D) Double point temperature

6. Pure metals generally have

(A) high conductivity and low temperature co-efficient

(B) high conductivity and large temperature co-efficient (Ans)

(C) low conductivity and zero temperature co-efficient

(D) low conductivity and high temperature co-efficient

7. Magnetostriction

(A) induced magnetism

(B) volume changes accompanying (Ans)

(C) rate of magnetisation

(D) rate of loss of magnetism

8. When ne and nh are the electron and hole densities, and µe and µh are the carrier mobilities, the Hall co-efficient is positive when,

(A) nh µh > ne µe

(B) nh µh2> ne µ2e (Ans)

(C) nh µh ne µ2e

9. Semi-conductor A has a higher band gap than semi-conductor B. If both A and B have the same dimensions, the same number of electrons at a given temperature and the same electron and hole mobilities, then

(A) A has the same number of holes as B

(B) A has a larger number of holes than B (Ans)

(C) A has a less number of holes than B

(D) Any of the above statements at (A), (B) or (C) could be true

10. Which of the following crystallographic defects contributes to electronic defects?

1. Thermal vibration

2. Point defects

3. Line defects

4. Surface defects

Select the correct answer using the codes given below

(A) 1,2 and 3 (Ans)

(B) 2,3 and 4

(C) 1,3 and 4

(D) 1,2 and 4

11. Above the curie temperature, the hysteresis loop of a ferroelectric material can be described by a

(A) parabola

(B) cycloid (Ans)

(C) straight line

(D) point

12. Orientational polarizations is

(A) inversely proportional to temperature and proportional to the square of the permanent dipole moment (Ans)

(B) proportional to temperature as well as to the square of the permanent dipole moment

(C) proportional to temperature and inversely proportional to the square of the permanent dipole moment

(D) inversely proportional to temperature as well as to the square of dipole moment

13. In a piezoelectric crystal oscillator, the oscillation or tuning frequency is linearly proportional to the

(A) mass of the crystal

(B) square root of the mass of the crystal

(C) square of the mass of the crystal

(D) inverse of the square root of the mass of the crystal (Ans)

14. Some of electrons are injected into the interior of a conductor surrounded by an insulator.

The injected electrons will

(A) distribute themselves uniformly

(B) distribute themselves randomly

(C) be confined at the point of injection

(D) travel to the surface of the conductor (Ans)

15. The isotope effect predicts that the super-conducting transition temperature should be proportional to (M is the atomic mass)

(A) M

(B) 1/M

(C) 1/?M (Ans)

(D) ?M

16. Consider the following statements : In the case of diamagnetic materials, the magnetic susceptibility is

1. Positive

2. Negative

3. Independent of temperature

4. Inversely proportional to temperature of these statements

(A) 1 and 3 are correct

(B) 2 and 3 are correct (Ans)

(C) 1 and 4 are correct

(D) 2 and 4 are correct

17. A small saw cut is made in a permanent magnet of toroidal shape. Which of the following are true for H0, if H0 is the magnetic field in the air-gap and Hi is that inside the magnet?

1. H0 < ?Hi?

2. H0 > ?Hi?

3. H0 is in the same direction as Hi

4. H0 and Hi are in opposite directions

Select the correct answer using the codes given below:

Codes:

(A) 1 and 3

(B) 1 and 4

(C) 2 and 3 (Ans)

(D) 2 and 4

18. Silicon contains 5*1028 atoms per cubic meter. If it is doped with two parts per million of arsenic , then the electron density at room temperature will be approximately.

(A) 4*1023 m3

(B) 1023 m-3 (Ans)

(C) 2*106 m-3

(D) 104 m-3

19. In a certain temperature range, the electrical conductivity of a semi-conductor increases with increase in temperature. This is because

(A) both carrier concentration and mobilty of carriers increase with increasing temperature

(B) both carrier concentration and mobility of carriers decrease with increasing temperatures

(C) the carrier concentration increase substantially, but the mobility of carriers decreases with increase in temperature (Ans)

(D) the carrier concentration remains constant but the mobility of carriers increases in temperature

20. The Hall-effect voltage in intrinsic silicon

(A) is positive

(B) is zero

(C) is negative (Ans)

(D) changes sign on application of magnetic field

21. The function of oxide layer in IC fabricaton is

2. to insulate surface electricity

3. to produce chemical stable surface

4. to increase the metling point

Consider above statement then correct are :

(A) 1, 2 and 3 (Ans)

(B) 2, 3 and 4

(C) 3, 4 and 1

(D) 3 and 4 only

22. Consider a single crystal of an intrinsic semi-conductor. The number of free carriers at the fermi level at room temperature is

(A) half the total number of electrons in the crystal

(B) half the number of free electrons in the crystal (Ans)

(C) half the number of atoms in the crystal

(D) zero

23. If the molecular structure and density of the material are known, then which of the following material parameters may be determined from the ?r versus 1/T plot?

(A) Sum of electronic and ionic polarizabilities (Ans)

(B) Lattice constant

(C) Breakdown voltage

(D) Loss constant

24 The electron relaxation time of metal A is 2.7*10-4 sec that of B is 1.35*10-4 sec. The ratio of resistivity of B to resistivity of A will be

(A) 4.0

(B) 2.0 (Ans)

(C) 0.5

(D) 0.25

25. Electrical conductivity of copper reduces with addition of a small amount of nickel because

(A) the mobility decreases due to creation of new scattering centres for electrons (Ans)

(B) nickel is ferromagnetic

(C) less free electrons are available for conduction

(D) the electrons of copper become bound to nickel atoms and are not free to move

26. Magnetic susceptibility of an ideal Type-I super-conductor in the super-conductivity state is

(A) -8

(B) -1 (Ans)

(C) between 0 and -1

(D) zero

27. When the transition occurs to the super conducting state, the magnetic flux is excluded from the material. This is known as

(A) Magnetophobic effect

(B) Silsbee effect

(C) Meissner effect (Ans)

(D) Copper effect

28. Cu2 MnAl is

(A) piezoelectric

(B) paramagnetic

(C) ferrimagnetic

(D) ferromagnetic (Ans)

29. In an intrinsic semi-conductor, the mobility of electrons in the conduction band is

(A) zero

(B) less than the mobility of holes in the valence band

(C) equal to the mobility of holes in the valence band

(D) greater than the mobility of holes in the valence band (Ans)

30. The effect of doping intrinsic semi- conductors is to

(A) move the fermi level away from the centre of the forbidden band (Ans)

(B) move the fermi level towards the centre of the forbidden band

(C) change the crystal structure of the semi-conductor

(D) keep the fermi level at the middele of the forbidden band

31. The hall co-efficient of sample (A) of a semi-conductor is measured at room temperature. The hall co-efficient of A at room temperature is 4*10-4 m3 colomb-1 . The carrier concentration in sample A at room temperature is

(A) ~ 10-4 m-3

(B) ~ 1024 m-3

(C) ~ 104 m-3

(D) ~ 1022 m-3 (Ans)

32. The hall angle ? of a metal sample is

(A) independent of the magnetic flux density B

(B) independent of the carrier mobility

(C) independent of the density of free carriers

(D) dependent on magnetic flux density, carrier mobility and density of free carriers (Ans)

33. The resistance of a thermistor is 5000 ? at 200 C and its resistance temperature co-efficient is 0.04/0C. A measurement with a lead resistance of 10 ? will cause an error of

(A) 0.050 C (Ans)

(B) 0.10 C

(C) 0.40 C

(D) 0.80 C

34. When a solid crystal of sodium is formed, the 3s-band will have

(A) half as many states as the number of atoms (Ans)

(B) same number of states as there are atoms

(C) twice as many states as there are atoms

(D) no states at all

35. The relaxation time (?) in a perfect dielectric is

(A) 0 (Ans)

(B) 1

(C) 1 < ? ?

(D) ?

36. The number of stress co-efficients or constants which characterize a piezoelectric material is

(A) 24 (Ans)

(B) 18

(C) 9

(D) 3

37. Which of the following pair (s) is/are correctly matched?

Material Application

1. Rochelle salt Phonograph

2. Barium titanate Amplifier

3. Quartz Oscillator

Select the correct answer using the codes given below :

(A) only 2

(B) 1 and 2

(C) 1 and 3 (Ans)

(D) 2 and 3

38. The conductivity of a metal at ultraviolet frequency (1014 Hz) approximately equals

(A) infinity

(B) zero

(C) d.c. conductivity

(D) half of d.c. conductivity (Ans)

39. Constantan is an alloy composed of

(A) 86% copper, 12% manganese and 2% nickel

(B) 76% nickel, 21% chromium, 2% manganese and 1% iron

(C) 60% copper and 40% nickel (Ans)

(D) 40% copper and 40% nickel and 20% carbon

40. Some of the characterizing parameters of a material are

1. Magnetic permeability

2. Electron relaxation time

3. Electron effective mass

4. Energy band gap

In case of metals, increase in one of the above parameters decreases its conductivity, while increase in another increase the conductivity. These two parameters are respectively.

(A) 1 and 3

(B) 3 and 2 (Ans)

(C) 4 and 3

(D) 1 and 2

41. What type of magnetic behaviour is observed in a type-I super-conductor?

(A) Perfect diamagnetism (Ans)

(B) Perfect paramagnetism

(C) Perfect ferromagnetism

(D) Perfect ferrimagnetism

42. The super-conducting transition temperature of lead is 7.26 K. If the initial field at OK is 64*103 Amp/m, then the critical field at 5 K is

(A) 0.3364*103 Amp/m

(B) 3.364*103 Amp/m

(C) 33.640*103 Amp/m (Ans)

(D) 336.400*103 Amp/m

43. Match List-I with List-II and select the correct answer using the codes given below the lists :

List-I List-II
(Material) (Classification)

(a) Mgo Fe2O3 1. Piezoelectric material

(b) BaTiO3 2. Ferrimagnetic material

(c) Cobalt 3. Ferromagnetic material

(d) Copper 4. Diamagnetic material

Codes :

(a) (b) (c) (d)

(A) 2 3 4 1

(B) 2 1 3 4

(C) 1 2 4 3

(D) 1 2 3 4

(Ans-B)

44. A paramagnetic material is used in an energy conversion process in which the following events occur:

1. Thermal energy is generated

2. Dipoles are turned

3. Magnetic field is generated

4. Material reacts to oppose it.

The correct sequence of these event is

(A) 3, 4, 2, 1

(B) 1, 4, 2, 3

(C) 1, 2, 4, 3

(D) 3, 2, 4, 1 (Ans)

45. A sample of iron carrying a current is subjected to a magnetic field. Match List-I with List-II to indicate the influence of angle between the magnetic field and current on the resistivity of the sample and select the correct answer using the codes given below the lists:

List-I List-II
(Direction of current) (Electrical resistivity)

(A) Parallel to magnetisation 1. Increase

(B) Perpendicular magnetisation 2. Decrease

3. Unchanged

Codes :

(a) (b)

(A) 1 2

(B) 2 1

(C) 2 3

(D) 3 1

(Ans-D)

46. Some magnetic materials may be classified on the basis of

1. Susceptibility

2. Saturation

3. Spin arrangement

4. Nature of hysteresis loop

5. Domain structure

6. Critical temperature above which it behaves as a paramagnetic material.

Out of these, those which can be used to distinguish between ferri and ferromagnetic matgerials would include

(A) 1, 3 and 4 (Ans)

(B) 2, 3 and 6

(C) 3, 4 and 5

(D) 3, 5 and 6

47. Assuming carrier mobility to be temperature independent, it can be shown that pure Si (Eg = 1.1 eV) and Ge (Eg = 0.7 eV) have the same conductivity at a temperature of

(A) 191 K

(B) 300 K

(C) 471 K

(D) 1470 K (Ans)

48. The processes that can be used to make the steel magnetically softer are

1. Annealing

2. Grain growth

3. Decarburization

4. Quenching

(A) 1, 2 and 3 (Ans)

(B) 2, 3 and 4

(C) 2 and 3 only

(D) 3 and 4 only

49. Polarization is a measure of

(A) dielectric constant per unit volume (Ans)

(B) voltage gradient of produce eslectrical breakdown

(C) product of charge and distance

(D) excess charge density

50 Consider the following semi-conductor diodes

1. Germanium diode

2. Silicon diode

3. Tunnel diode

4. Schottky diode

The correct increasing order of forward voltage drop of these diodes is

(A) 1,3,2,4

(B) 1,2,3,4

(C) 3,4,2,1

(D) 3,1,4,2 (Ans)