BSNL Junior Telecom Officers’ (JTO) Exam Question Paper 2014 With Answer Key

BSNL Junior Telecom Officers’ (JTO) Recruitment Exam Question Paper-2014

Section-I Engineering Stream

1. If the voltage applied across a capacitance is triangular in waveform then the waveform of the current is

(A)  Triangular

(B)  Trapezoidal

(C)  Sinusoidal

(D)  Rectangular.

2. One of the following statement which is true for relative dielectric constant is

(A)  it is dimensionless

(B)  it is not equal to unity for vacuum

(C)  it’s value for all substances is less than one

(D)  none of these

3. Pure metals generally have

(A)  high conductivity and low temperature coefficient

(B)  high conductivity and large temperature coefficient

(C)  low conductivity and zero temperature coefficient

(D)  low conductivity and high temperature coefficient

4. For small size, high frequency coils, the most common core material is

(A)  Air

(B)  Ferrite

(C)  Powdered ion

(D)  Steel

5. For an abrupt junction Varactor diode, the dependence of device capacitance (C) on applied reverse bias (V) is given by

(A)  C ∝ V1/3

(B)  C ∝ V−1/3

(C)  C ∝ V1/2

(D)  C ∝ V1/2

6. A superconductor is a

(A)  material showing perfect conductivity and Meissner effect below a critical temperature

(B)  conductor having zero resistance

(C)  perfect conductor with highest diamagnetic susceptibility

(D)  perfect conductor which becomes resistive when the current density through it exceeds a critical value

7. When a semiconductor based temperature transducer has a temperature coefficient of −2500 mV/℃ then this tranducer is indeed a

(A)  Thermistor

(B)  Forward biased pn junction diode

(C)  Reverse biased pn junction

(D)  FET

8. The location of lightning arrestor is

(A)  near the transformer

(B)  near the circuit breaker

(C)  away from the transformer

(D)  None

9. Time constant of an RC circuit increases if the value of the resistance is

(A)  increased

(B)  decreased

(C)  neither (A) nor (B)

(D)  both (A) and (B)

10. Intrinsic semiconductors are those which

(A)  are available locally

(B)  are made of the semiconductor material in its purest from

(C)  have more electrons than holes

(D)  have zero energy gaps

11. The primary control on drain current in a JPFET is exerted by

(A)  Channel resistance

(B)  Size of depletion regions

(C)  Voltage drop across channel

(D)  Gate reverse bias

12. The electrical conductivity of metals which is expressed in ohm1 m1 is of the order of

(A)  1010

(B)  105

(C)  104

(D)  106

13. When biased correctly, a zener diode –

(A)  acts as a fixed resistance

(B)  has a constant voltage across it

(C)  has a constant current passing through it

(D)  never overheats

14. The current amplification factor αde is given by –

(A)  IC/IE

(B)  IC/IB

(C)  IB/IC

(D)  IB/IC

15. Compared to bipolar, FETs have-

(A)  high input impedance

(B)  low input impedance

(C)  same input impedance

(D)  none

16. The source-drain channel of JFET is

(A)  ohmic

(B)  bilateral

(C)  unilateral

(D)  both (A) and (B)

17. Diac is equivalent to a

(A)  pair of SCRs

(B)  pair of four layer SCRs

(C)  Diode and two resistors

(D)  Triac width

18. When a sample of N type semiconductor has electron density of 6.25 × 1018/cm3 at 300K and if the intrinsic concentration of carriers in this sample is 2.5 × 1013/cm3 then the hole density will be-

(A)  106/cm3

(B)  107/cm3

(C)  1010 cm3

(D)  1012/cm3

19. The statement “In any network of linear impedances, the current flowing at any point is equal to the algebraic sum of the currents caused to flow at that point by each of the sources of emf taken separately with all other emf’s reduced to zero” represents

(A)  Kirchhoff’s law

(B)  Norton’s theorem

(C)  Thevenin’s theorem

(D)  Superposition theorem

20. One of the following modes which has the characteristics of attenuation becoming less as he frequency is increased and is attractive at microwave frequencies of circular cylindrical wave guides is-

(A)  TEmode

(B)  TM01 mode

(C)  TE­01 mode

(D)  Higher order mode

21. A two-port network is symmetrical if –

(A)  z11z22 – z12z21 = 1

(B)  h11h22 – h12h21 = 1

(C)  AD – BC = 1

(D)  y11y22 – y12y21 = 1

22. For transmission line load matching over a range of frequencies, it is best to use a

(A)  balun

(C)  double stub

(D)  single stub of adjustable position

23. The poles and zeros of a driving point function of a network are simple and interlace on the negative real axis with a pole closest to the origin. It can be realized.

(A)  by an LC network

(B)  as an RC driving point impedance

(C)  as an RC driving point admittance

(D)  only by an RLC network

24. Poles and zeros of a driving point function of a network are simple and interlace on the jw axis. The network consists of elements-

(A)  R and C

(B)  L and C

(C)  R and L

(D)  R, L and C

25. For a two point reciprocal network, the output open circuit voltage divided by the input current is equal to-

(A)  B

(B)  Z12

(C)  1/y12

(D)  h12

26. In a short electric doublet the radiation properties are so that-

(A)  the induction field diminishes as the square root of the distance and is only appreciable in the vicinity of the conductor.

(B)  in the radiation, magnetic field is minimum when the current is maximum.

(C)  the radiation resistance of a short doublet antenna is extremely high.

(D)  mean rate of power through a u nit area of spherical sphere surrounding this doublet is proportional to the square of the elemental length, other factors remaining constant.

27. The frequency modulated (FM) radio frequency range is nearly

(A)  250 – 300 MHz

(B)  150 – 20 MHz

(C)  90 – 105 MHz

(D)  30 -70 MHz

28. In an underground cable the distortion in the transmission of carrier frequency can be eliminated by using

(D)  Shielding

29. The characteristic impedance of a transmission line with inductance 0.294 mH/m and capacitance 60 pM/m is

(A)  49 W

(B)  60 W

(C)  70 W

(D)  140 W

30. For a quarter wavelength ideal transmission line of characteristic impedance 50 ohms and load impedance 100 ohms, the input impedance will be a-

(A)  25W

(B)  50W

(C)  100W

(D)  150W

31. The depth of penetration or skin depth for an electromagnetic field of frequency ‘f’ in a conductor of resistivity r and permeability m is-

(A)  inversely proportional to r and f and directly proportional to m

(B)  directly proportional to r and inversely proportional to f and m

(C)  directly proportional to f and inversely proportional to r and m

(D)  inversely proportional to r and m and directly proportional to f

32. When an antenna has a gain of 44dB then assuming that the main beam of the antenna is circular in cross-section the beam width will be-

(A)  0.44560

(B)  1.44560

(C)  2.44560

(D)  3.44560

33. Lens antennas used for microwaves are usually made of

(A)  Polystyrene

(B)  Glass of low refractive index

(C)  Paraboloid Surfaces

(D)  Dielectric media having large refractive index

34. One of the following types of instrument which is an electrometer is-

(A)  Electrodynamometer

(B)  PMMC

(C)  Electrostatic

(D)  Moving iron

35. When an ac current of 5A and dc current of 5A flow simultaneously through a circuit then which of the following statement is true?

(A)  An ac ammeter will read less than 10A but more than 5A

(B)  An ac ammeter will read only 5A

(C)  A dc ammeter will read 10A

(D)  A dc ammeter will read zero

36. When Q factor of a circuit is high, then

(A)  power factor of the circuit is high

(B)  impedance of the circuit is high

(C)  bandwidth is large

(D)  more narrow bandwidth

37. The resolution of a logic analyser is

(A)  the maximum number of input channels

(B)  the minimum duration of the glitch it can capture

(C)  it’s internal clock period

(D)  the minimum amplitude of input signal it can display

38. A memoryless system is a-

(A)  causal

(B)  not causal

(C)  nothing can be said

(D)  none

39. An air capacitor is a-

(A)  time variant

(B)  active device

(C)  time invariant

(D)  time invariant and passive device

(A)  pure metals

(B)  pure insulators

(C)  sintered mixtures of metallic oxides

(D)  pure semiconductor

41. Pirani gauge is used to measure-

(A)  very low pressures

(B)  high pressures

(C)  pressures in the region of 1 atm

(D)  fluid flow

42. These circuits converts input power at one frequency to output power at a different frequency through one stage conversion –

(A)  AC Voltage controllers

(B)  Cyclo converters

(C)  Phase controlled rectifiers

(D)  Inverters

43. In a forward voltage triggering thyri9stor changes from-

(A)  OFF state to ON state

(B)  ON state to OFF state

(C)  ON state to ON state

(D)  OFF state to OFF state

44. A thyristor, when triggered, will change from forward blocking state to conduction state if its anode to cathode voltage is equal to

(A)  peak repetitive off state of forward voltage

(B)  peak working off state forward voltage

(C)  peak working off state reverse voltage

(D)  peak non-repetitive off state forward voltage

45. Gate characteristic of a thyristor –

(A)  is a straight line passing through origin

(B)  is of the type Vg = a + bIg

(C)  is a curve between Vg and Ig.

(D)  has a spread between two curves of Vg – Ig

46. A four quadrant operation requires –

(A)  two full converters in series

(B)  two full converters connected back to back

(C)  two full converters connected in parallel

(D)  two semi converters connected back to back

47. If for a single phase half bridge inverter, the amplitude of output voltage is Vs and the output power is P, then their corresponding values for a single phase full bridge inverter are –

(A)  Vs, P

(B)  Vs/2, P

(C)  2Vs, 2P

(D)  2Vs, P

48. In an enhancement type MOSFET the output V-I characteristics has-

(A)  only an ohmic region

(B)  only a saturation region

(C)  only ohmic region at 10 W voltage value followed by a saturation region at higher voltages

(D)  an ohmic region at large voltage values preceded by a saturation region at lower voltages

49. The energy gap in a semiconductor

(A)  increases with temperature

(B)  remains constant

(C)  slightly increases with temperature

(D)  decreases with temperature

50. In an electronic circuit matching means

(A)  connecting a high impedance directly to low impedance

(B)  selection of components which are compatible

(C)  transferring maximum amount of signal between different kinds of circuits

(D)  C coupled stages

Section – II Engineering Stream

51. P channel FETs are less superior than N channel FETs because

(A)  they have higher input impedance

(B)  they have high switching time

(C)  they consume less power

(D)  mobility of electrons is greater than that of holes

52. Small increase in temperature in the CE connected transistor is the

(A)  increase in ICEO

(B)  increase in ac current gain

(C)  decrease in ac current gain

(D)  increase in output resistance

53. An amplifier has band width of 20 KHz and a midband gain of 50 without feedback. If a negative feedback of 1% is applied then bandwidth with feedback is

(A)  13.3 KHz

(B)  30 KHz

(C)  10 KHz

(D)  40 KHz

54. The output of a class B amplifier

(A)  is distortion free

(B)  consist of positive half cycles only

(C)  is like the output of a full wave rectifier

(D)  comprises short duration current pulses

55. An amplifier with negative feedback

(A)  lowers its lower 3 dB frequency

(B)  raises its upper 3 dB frequency

(C)  increases its bandwidth

(D)  all of the above

56. What changes would be necessary in block C if FM signals are to be received?

(A)  block becomes redundant

(B)  a FM detector would be required

(C)  a high frequency signal generator

(D)  an additional local oscillator will be needed

57. The main disadvantage of Diode-Transistor logic (DTL) is its –

(A)  greater speed

(B)  slower speed

(C)  average speed

(D)  none of the above

58. Time delay ∆t in digital signals in an SISO shift register is given by

(A)  ∆t = N × Fe

(B)  ∆t = N × 1/Fe

(C)  ∆t = 1/N × Fe

(D)  ∆t = N – 1/Fe

59. The output Qn is 1 in a JK flip and it does not change when clock pulse is applied) The possible combination of Jn and Kn can be – (y denotes don’t care)

(A)  y and 0

(B)  y and 1

(C)  0 and y

(D)  1 and y

60. Basic memory cell of dynamic RAM consists of –

(A)  a flip flop

(B)  a transistor acting as a capacitor

(C)  a transistor

(D)  a capacitance

61. The 2’s complement of 10002 is-

(A)  0111

(B)  0101

(C)  1000

(D)  0001

62. Master slave flip-flop is made up of-

(A)  two flip flops connected in series

(B)  two flip flops connected in parallel

(C)  debouncer circuit

(D)  a D-latch

63. Number of nibbles making one byte is

(A)  2

(B)  4

(C)  8

(D)  16

64. The intrinsic impedance of free space –

(A)  is independent of frequency

(B)  decreases with increase of frequency

(C)  increases with increase of frequency

(D)  varies as square root of frequency

65. A system consists of 12 poles and 2 zeroes. It high frequency asymptote in its magnitude plot has a slope of

66. Considering the conditions

1. High loop gain

2. Less ringing

3. Greater damping

4. Negative dB gain margin

System stability requirements would include?

(A)  1 and 3

(B)  1, 2 and 3

(C)  1 and 4

(D)  2, 3 and 4

67. In the equatorial plane only Geosynchronous satellite are launched because it is the only plane which provides –

(A)  24 hour orbit

(B)  stationary satellite

(C)  global communication

(D)  zero-gravity environs

(A)  space multiplexing

(B)  time multiplexing

(C)  frequency multiplexing

(D)  none of the above

69. PAM signals can be demodulation by using a

(A)  Low Pass Filters (LPE) alone

(B)  Schmitt trigger followed by a LPF

(C)  differentiator followed by a LPF

(D)  clipper circuit by a LPF

70. In a FDM receiver channels can be separated by using –

(A)  AND gates

(B)  Band pass

(C)  Differentiation

(D)  Integration

71. The most common modulation system used for telegraphy is –

(A)  Frequency Shift Keying

(B)  Two – Tone Modulation

(C)  Pulse Code Modulation

(D)  Single Tone Modulation

72. Use of varactor diode in generation of modulated signal be

(A)  FM generation only

(B)  100 AM generation only

(C)  PM generation only

(D)  both PM and AM generation

(A)  reduce X-ray emission

(B)  ensure that each beam strikes only its own dots

(C)  increase screen brightness

(D)  provide degaussing for the screen

74. The circuit that separates composite video waveform from the sync pulses is –

(A)  the keyed AGC amplifier

(B)  a clipper

(C)  an integrator

(D)  a sawtooth current

75. Band width of microwaves is –

(A)  1 GHz – 103 GHz

(B)  1 GHz – 100 GHz

(C)  1 GHz – 10 GHz

(D)  1 GHz – 106 GHz

76. In transverse Magnetic mode –

(A)  no electric line is in direction of propagation

(B)  no magnetic line is in direction of propagation

(C)  both magnetic & electric lines are in direction of propagation

(D)  neither magnetic nor electric lines in direction of propagation

77. Signal transmission on sky wave propagation is due to-

(A)  Refraction of wave

(B)  Reflection of wave

(C)  Pieris through inosphere

(D)  None

78. According to Barkhausen Criterion Phase shift of signal should be-

(A)  60°

(B)  90°

(C)  180°

(D)  360°

79. The transmission does not have

(A)  Partition noise

(B)  Flicker noise

(C)  Resistance

(D)  Short noise

80. Varoctor diode has non linearity of

(A)  capacitance

(B)  inductance

(C)  resistance

(D)  is a linear device

81. Noise figure is calculated as –

(A)  i/p S/N Ratio × o/p S/N Ratio

(B)  i/p S/N Ratio / o/p S/N Ratio

(C)  (i/p S/N Ratio / o/p S/N Ratio) × 100

(D)  i/p S/N Ratio + o/p S/N Ratio

82. You can determine quickly the effect of adding poles and zeros by-

(A)  Nicholas chart

(B)  Nyquist plot

(C)  Bode plot

(D)  Root locus

83. The polar plot of  intercepts real axis at w = wo. Then, the real part and wo are given by

(A)  −5, 1

(B)  −2.5, 1

(C)  −5, 0.5

(D)  −5, 2

84. Laplace transform F(s) of a function of f(E) is given by  The initial and final values of F(t) will be respectively –

(A)  zero and 1

(B)  zero and 10

(C)  10 and zero

(D)  70 and 80

85. A satellite link uses different frequencies for receiving and transmitting in order to –

(A)  avoid interference from terrestrial microwave links

(B)  avoid interference between its powerful transmitted signals and weak incoming signal

(C)  minimize free-space losses

(D)  maximize antenna gain.

86. The first determining factor in selecting a satellite system is its-

(A)  EIRP

(B)  Antenna size

(C)  Coverage area

(D)  Antenna gain

87. Equalizing pulses in TV are sent during –

(A)  horizontal blanking

(B)  vertical blanking

(C)  the serrations

(D)  the horizontal retrace

88. Silicon has a preference in IC technology because

(A)  it is an indirect semiconductor

(B)  it is a covalent semiconductor

(C)  it is an elemental semiconductor

(D)  of the availability of nature oxide SiO

89. The R.M.S. value of a half wave rectified sinusoidal alternating current with peak value Im is

(A)  Im/1

(B)  Im/√2

(C)  Im/2

(D)  Im­/√3

90. The transient current in lossless L-C circuit when exited from AC source is, _____ sine wave

(A)  Critically damped

(B)  Underdamped

(C)  Overdamped

(D)  Undamped

91. A transmission line is terminated at its characteristic impedance. The reflection coefficient is

(A)  1

(B)  −1

(C)  0

(D)  ∞

92. In a series RLC circuit operation below the resonant frequency the current

(B)  I lags Vs

(C)  I is in phase with Vs

(D)  None of these

93. To distinguish between signals having very close values, we need an instrument with

(A)  high accuracy

(B)  high resolution

(C)  high sensitivity

(D)  high linearity

94. The semiconductor used for LEDs emitting in the visible range is

(A)  GaAs

(B)  GaAℓAs

(C)  GalnAs

(D)  GaAsP

95. Which of the following pairs of crystal structure possesses the same atomic packing density?

(A)  Simple Cubic & Body Centred Cubic

(B)  Body Centred Cubic & Face Centred Cubic

(C)  Face Centered Cubic & Hexagonal Close Packed

(D)  Body Centred Cubic & Hexagonal Close Packed

96. The colouor bands on a carbon composition resistor occur in the sequence:

yellow, violet, yellow and silver.

Its resistance is

(A)  470 KΩ ± 47%

(B)  470 KΩ ± 23.5%

(C)  47 KΩ ± 10%

(D)  47 KΩ ± 5%

97. A radio receiver is placed at one corner of a table and again placed at some other corner of the same table. Loudspeaker output is changed because

(A)  image interference is reduced

(B)  adjacent channel interference is increased

(D)  line of sigh propagation is not utilized

98. In a Klystron amplifier, the RF voltage producers

(A)  Amplitude Modulation

(B)  Frequency Modulation

(C)  Phase Modulation

(D)  Velocity Modulation

99. For an antenna to be frequency-independent it should expand or contract in proportion to the

(A)  gain

(B)  directivity

(C)  wavelength

(D)  impedance

100. In class-A power amplifier, the collector dissipation is maximum when

(A)  MOV A, A

(B)  ANI 00H

(C)  XRA A

(D)  CMP A

Section – III General Ability Test

101. The son seems to have ____ from his father a somewhat gloomy and moody manner.

(A)  washed

(B)  inherited

(D)  attempt

102. Essayist works with words as sculptor with

(A)  water

(B)  stone

(C)  air

(D)  hills

103. What is a collection of sheep called?

(A)  bunch

(B)  flock

(C)  herd

(D)  comet

104. Join these sentence meaningfully by choosing the correct alternative from the following You can buy a book. You can read it.

(A)  and

(B)  nor

(C)  either

(D)  neither

105. What is the opposite of Asperity –

(A)  gentility

(B)  superiority

(C)  kindness

(D)  clarity

106. The Election Commission functions under –

(A)  Ministry of Home Affairs

(B)  Ministry of Law

(C)  Prime Minster’s Secretariat

(D)  None of these

107. Article 352 of Indian Constitution needs to be revoked in case –

(A)  President’s Rule is to be imposed

(B)  Emergency is declared

(C)  Services of a Government servant are to be terminated without any enquiry

(D)  A political party of national level is to be banned

108. Radio-activity was first discovered by-

(A)  Becquerel

(C)  Rutherford

(D)  Jenner

109. Ninth Five Year Plan in India ranges from –

(A)  1995 – 2000

(B)  1996 – 2001

(C)  1997 – 2002

(D)  1998 – 2003

110. How much electricity does India propose to generate through nuclear power by the year 2014 AD?

(A)  15,000 MW

(B)  35,000 GW

(C)  25,000 MW

(D)  40,000 GW

111. In which year did the fall of Bastille take place?

(A)  1769

(B)  1789

(C)  1889

(D)  1869

112. To form a quorum how many members of the Lok Sabha or Rajya Sabha should be present?

(A)  1/10th of total membership

(B)  1/6th of total membership

(C)  1/4th of total membership

(D)  1/5th of total membership

113. How many countries are non-permanent members of the Security Council?

(A)  6

(B)  7

(C)  9

(D)  10

114. The International Date Line is represented by

(A)  100° meridian

(B)  0° meridian

(C)  180° meridian

(D)  90° meridian

115. India’s first satellite was launched from –

(A)  Sriharikota

(B)  Cape Kennedy

(C)  Bangalore

(D)  Soviet cosmodrome

116. Name of the author of the famous book “Politics” –

(A)  Aristotle

(B)  Socrates

(C)  Plato

(D)  None of these

117. “Guernica” is Picasso’s painting on –

(A)  The Spanish Civil War

(B)  The American Civil War

(C)  The French Revolution

(D)  The Russian Revolution

118. The object of the Supreme Court’s Keshvanand Bharati ruling is

(A)  to put a limit on Parliament’s amendatory powers

(B)  to give unlimited powers to Parliament to amend the Constitution

(C)  to give precedence to Directive principles over Fundamental Rights

(D)  None of these

119. Which country in July’99 officially announced mastering of indigenously developed neutron bomb technology?

(A)  Korea

(B)  France

(C)  India

(D)  China

120. Shifting cultivation is commonly used in which of the following states?

(B)  Maharashtra

(C)  Jammu and Kashmir

(D)  Nagaland