BSNL Junior Telecom Officers’ (JTO) Recruitment Exam Question Paper 2008 With Answer Key

BSNL Junior Telecom Officers’ (JTO) Recruitment Exam

Question Paper- JUNE 2008

Section-I

1. The depth of penetration of 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 tor and m

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

Answer: (B)

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

(A)  0.4456°

(B)  1.4456°

(C)  2.4456°

(D)  3.4456°

Answer: (C)

3. 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

Answer: (A)

4. One of the following types of instrument which is an electrometer is

(A)  Electrodynamometer

(B)  PMMC

(C)  Electrostatic

(D)  Moving iron

Answer: (C)

5. 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

Answer: (A)

6. 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)  None of these

Answer: (D)

7. 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

Answer: (D)

8. A memoryless system is

(A)  causal

(B)  not causal

(C)  nothing can be said

(D)  None of these

Answer: (A)

9. An air capacitor is a

(A)  time variant

(B)  active device

(C)  time invariant

(D)  time invariant and passive device

Answer: (D)

10. Thermistors are made of

(A)  pure metals

(B)  pure insulators

(C)  sintered mixtures of metallic oxides

(D)  pure semiconductor

Answer: (C)

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

(A)  balun

(B)  broad band directional coupler

(C)  double stub

(D)  single stub of adjustable position

Answer: (A)

12. The poles and zeros of a driving point function of a network are simple and interlace on the negative real axis with a people 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

Answer: (D)

13. Poles and zeros of a driving point function o f 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

Answer: (B)

14. For a two port reciprocal network, the output open circuit voltage divided by the input current is equal to

(A)  I12

(B)  Z12

(C)  V12

(D)  h12

Answer: (B)

15. 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 unit area of spherical sphere surrounding this doublet is proportional to the square of the elemental length, other factors remaining constant.

Answer: (D)

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

(A)  250 – 300 MHz

(B)  150 – 200 MHz

(C)  90 – 105 MHz

(D)  30 – 70 MHz

Answer: (C)

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

(A)  Inductive loading

(B)  Resistive loading

(C)  Capacitive loading

(D)  Shielding

Answer: (A)

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

(A)  49 W

(B)  60 W

(C)  70 W

(D)  140 W

Answer: (C)

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

(A)  25 W

(B)  50 W

(C)  100 W

(D)  150 W

Answer: (A)

20. The 2’s complement of 10002 is

(A)  0111

(B)  0101

(C)  1000

(D)  0001

Answer: (C)

21. Master slave flip-flop is made up of

(A)  two flip flops connected in series

(B)  two flip flops connected in parallel

(C)  a debouncer circuit

(D)  a-D-latch

Answer: (A)

22. Number of nibbles making one byte is

(A)  2

(B)  4

(C)  8

(D)  16

Answer: (A)

23. The intrinsic impedance of free space

(A)  is independent of frequency

(B)  decrease with increase of frequency

(C)  increases with increase of frequency

(D)  varies as square root of frequency

Answer: (A)

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

(A)  −200 dB/decade

(B)  −240 dB/decade

(C)  −230 dB/decade

(D)  −320 dB/decade

Answer: (A)

25. 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

Answer: (D)

26. In the equatorial only Geo-synchronous 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

Answer: (B)

27. Radio Broadcasting is an example of

(A)  space multiplexing

(B)  time multiplexing

(C)  frequency multiplexing

(D)  None of these

Answer: (C)

28. PAM signals can be demodulation by using a

(A)  Low pass filters (LPE) alone

(B)  A Schmitt trigger followed by a LPF

(C)  A differentiator followed by a LPF

(D)  A clipper circuit by a LPF

Answer: (D)

29. In an FDM receiver channels can be separated by using

(A)  AND gates

(B)  Band pass

(C)  differentiation

(D)  Integration

Answer: (A)

30. Pirani gauge is used to measure

(A)  very low pressures

(B)  high pressures

(C)  pressures in the region of 1 atm

(D)  fluid flow

Answer: (A)

31. 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

Answer: (B)

32. In a forward voltage Triggering thyristor 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

Answer: (A)

33. 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 forward voltage

(B)  peak working off state forward voltage

(C)  peak working off state reverse voltage

(D)  peak non-repetitive off state forward voltage

Answer: (B)

34. Gate characteristic of thyristor

(A)  is a straight line passing through origin

(B)  is of the type Vu = a + bIg

(C)  is a curve between V­g and Ig

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

Answer: (D)

35. 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

Answer: (B)

36. 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

Answer: (C)

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

(A)  only on 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

Answer: (C)

38. The energy gap in a semiconductor

(A)  increase with temperature

(B)  remains constant

(C)  slightly increases with temperature

(D)  decrease with temperature

Answer: (D)

39. 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)  RC coupled stages

Answer: (C)

40. 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

Answer: (D)

41. 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

Answer: (B)

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

(A)  Air

(B)  Ferrite

(C)  Powdered ion

(D)  Steel

Answer: (A)

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

(A)  C α VI/3

(B)  C α V-I/3

(C)  C α VI/2

(D)  C α V-I/2

Answer: (B)

44. A superconductor is a

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

(B)  A conductor having zero resistance

(C)  A perfect conductor with highest diamagnetic susceptibility

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

Answer: (A)

45. When a semiconductor based temperature transducer has a temperature coefficient of – 2500 mV/0C then this transducer is indeed a

(A)  Thermistor

(B)  Forward biased pn junction diode

(C)  Reverse biased pn junction diode

(D)  FET

Answer: (B)

46. The location of lightning arrestor is

(A)  Near the transformer

(B)  Near the circuit breaker

(C)  Away from the transformer

(D)  None of these

Answer: (A)

47. 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)

Answer: (A)

48. Intrinsic semiconductors are those which

(A)  Are available locally

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

(C)  Have more electrons than holes

(D)  Have zero energy gaps

Answer: (B)

49. The primary control on drain current in a JFET is exerted by

(A)  Channel resistance

(B)  Size of depletion regions

(C)  Voltage drop across channel

(D)  Gate reverse bias

Answer: (D)

50. 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

Answer: (D)

Section-II

51. 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

Answer: (A)

52. An amplifier has a 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

Answer: (B)

53. The output of a class B amplifier

(A)  is distortion free

(B)  consists of positive half cycles only

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

(D)  comprises short duration current pulses

Answer: (B)

54. 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

Answer: (D)

55. 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

Answer: (B)

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

(A)  greater speed

(B)  slower speed

(C)  average speed

(D)  None of these

Answer: (B)

57. Time delay Dt in digital signals in an SIS O shift register is given by

(A)  Dt = N ´ Fc

(B)  Dt = N ´ 1/Fc

(C)  Dt = 1/N ´ Fc

(D)  Dt = N, 1/Fc

Answer: (B)

58. The output Qn is 1 in a JK flip flop and its does not change when clock pulses is applied) The possible combination of Jn and Kn can be (Y denotes don’t care)

(A)  y and o

(B)  y and 1

(C)  0 and y

(D)  1 and y

Answer: (A)

59. 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

Answer: (B)

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

(A)  1010

(B)  105

(C)  104

(D)  106

Answer: (B)

61. 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

Answer: (B)

62. The current amplification factor adc is given by

(A)  IC/IE

(B)  IC/IB

(C)  IB/IC

(D)  IB/IC

Answer: (A)

63. Compared to bipolar, FETs have

(A)  high input impedance

(B)  low input impedance

(C)  same input impedance

(D)  none

Answer: (A)

64. The source-drain channel of JFET is

(A)  ohmic

(B)  bilateral

(C)  unilateral

(D)  both (A) and (B)

Answer: (D)

65. Diac is equivalent to a

(A)  Pair of SCRs

(B)  Pair of four layer SCRs

(C)  Diode and two resistors

(D)  Triac width

Answer: (B)

66. When a sample of N type semiconductor has electron density of 6.25 × 1011/cm3 at 300 K and if the intrinsic concentration of carriers in this sample is 2.5 × 1012/cm3 then the hole density will be

(A) 106/cm3

(B)  103/cm3

(C)  1010/cm3

(D)  1012/cm3

Answer: (B)

67. 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

Answer: (D)

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

(A)  TE1 mode

(B)  TM01 mode

(C)  TE01 mode

(D)  Higher order mode

Answer: (C)

69. A two-port network is symmetrical if

(A)  z11z22 – z12z21 = 1

(B)  h11h22 – h12h21 = 1

(C)  AD – BC = 1

(D)  y1y22 – y12y21 = 1

Answer: (C)

70. The International Date Line is represented by

(A)  100° meridian

(B)  120° meridian

(C)  180° meridian

(D)  90° meridian

Answer: (C)

71. India’s first satellite was launched from

(A)  Sriharikota

(B)  Cape Kennedy

(C)  Bangalore

(D)  A Soviet cosmodrome

Answer: (A)

72. Name the author of the famous book “Politics”.

(A)  Aristotle

(B)  Socrates

(C)  Plato

(D)  None of them

Answer: (A)

73. “Guernica” is Picasso’s painting on

(A)  The Spanish Civil War

(B)  The American Civil War

(C)  The French Revolution

(D)  The Russian Revolution

Answer: (A)

74. 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

Answer: (A)

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

(A)  N. Korea

(B)  France

(C)  India

(D)  China

Answer: (D)

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

(A)  Tamil Nadu

(B)  Maharashtra

(C)  Jammu and Kashmir

(D)  Nagaland

Answer: (D)

77. The polar plot of G(S) = 10/s(s + 1)2 intercepts real axis at ω = ωo. Then, the real part and wo are given by?

(A)  −5, 1

(B)  +5, −1

(C)  −5, −1

(D)  5, 1

Answer: (A)

78. 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

Answer: (C)

79. 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

Answer: (A)

80. Use of VAROCTOR 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

Answer: (A)

81. In colour picture tube shadow mask is used to

(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

Answer: (C)

82. The circuit that separates composite video warefore from the sync pulses is

(A)  the keyed AGC amplifar

(B)  a clipper

(C)  an integrator

(D)  a saw tooth current

Answer: (D)

83. 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

Answer: (A)

84. In transverse Magnetic mode

(A)  no electric line is in direction of propagation

(B)  no magnetic line is in direction of propagation

(C)  bath magnetic & electric lines are is direction of propagation

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

Answer: (B)

85. Signal transmission in sky wave propagation is due to

(A)  Reforction of wave

(B)  Reflection of wave

(C)  Pierus through Inosphere

(D)  None of these

Answer: (A)

86. According to Barkhausen Criterion Phase shift of signal should be

(A)  60°

(B)  90°

(C)  180°

(D)  360°

Answer: (D)

87. The transmission does not have

(A)  Partition noise

(B)  Flicker noise

(C)  resistance

(D)  Short noise

Answer: (A)

88. Join these sentences 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

Answer: (A)

89. What is the opposite of ASPERITY?

(A)  gentility

(B)  superiority

(C)  kindness

(D)  clarity

Answer: (B)

90. The Election Commission functions under

(A)  Ministry of Home Affairs

(B)  Ministry of Law

(C)  Prime Minister’s Secretariat

(D)  None of these

Answer: (D)

91. 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

Answer: (B)

92. Radio-activity was first discovered by

(A)  Becquerel

(B)  Madam Curie

(C)  Rutherford

(D)  Jenner

Answer: (A)

93. Ninth Plan in India ranges from

(A)  1995-2000

(B)  1996-2001

(C)  1997-2002

(D)  1998-2003

Answer: (C)

94. How much electricity does India propose to generate through nuclear power by the year 2000 AD?

(A)  5,000 MW

(B)  10,000 MW

(C)  15,000 MW

(D)  20,000 MW

Answer: (B)

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

(A)  1769

(B)  1789

(C)  1889

(D)  1869

Answer: (B)

96. 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

Answer: (A)

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

(A)  6

(B)  7

(C)  9

(D)  10

Answer: (D)

98. VAROCTOR DIODE has non-linearity of

(A)  Capacitances

(B)  Inductance

(C)  Resistance

(D)  Is a linear device

Answer: (C)

99. Noise figure is calculated as

(A)  1/P signal to noise ratio X O/P signal to noise ratio

(B)  1/P S/N Ratio / O/P S/N Ratio

(C)  1/P S/N Ratio / O/P S/N Ratio × 100

(D)  1/P S/N Ratio + O/P S/N Ratio

Answer: (D)

100. You can determines quickly the effect of adding poles and zeros by

(A)  Nicholas chart

(B)  Nyquist plot

(C)  Bode plot

(D)  Root locus

Answer: (C)

Section-III

101. If there exists at least one path between any pair of vertices in a graph , the graph is known as

(A)  complete graph

(B)  disconnected graph

(C)  connected graph

(D)  Euler graph

Answer: (C)

102. Laplace transform F (s) of a function f(E) is given by F(s) = 10 (s + 7)/(s + 1) (s + 8) (s + 10)

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

Answer: (C)

103. A satellite l ink uses different frequencies for receiving and transmitting in order to

(A)  avoid interference from terrestrial microwaves links

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

(C)  minimize free-space losses

(D)  maximize antenna gain

Answer: (B)

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

(A)  EIRP

(B)  Antenna size

(C)  Coverage area

(D)  Antenna gain

Answer: (C)

105. Equalizing pulses in TV are sent during

(A)  horizontal blanking

(B)  vertical blanking

(C)  the serrations

(D)  the horizontal retrace

Answer: (B)

106. The son seems to have …. from his father a somewhat gloomy and moody manner.

(A)  washed

(B)  inherited

(C)  admired

(D)  attempt

Answer: (B)

107. Essayist works with words as sculptor with

(A)  water

(B)  stone

(C)  air

(D)  hills

Answer: (B)

108. What is a collection of sheep called ?

(A)  bunch

(B)  flock

(C)  herd

(D)  comet

Answer: (B)

109. Who is the author of famous book “My Country My Life” ?

(A)  Sonia Gandhi

(B)  APJ. Abdul Kalam

(C)  Nelson Mandela

(D)  L. K. Advani

Answer: (D)

110. Choose the best expresses the meaning of the given word – ‘LAVISH’

(A)  Profuse

(B)  Showy

(C)  Gay

(D)  Carefree

Answer: (A)

111. Choose the word opposite in meaning to the given word – ‘HARMONY’.

(A)  Hatred

(B)  Friction

(C)  Discord

(D)  Enmity

Answer: (C)

112. Find the word or phrase opposite in meaning of the italics word or phrase.

Ambiguity of thoughts can prove disastrous

(A)  Rigidity

(B)  Clarity

(C)  Certainty

(D)  Rationality

Answer: (B)

113. Complete the sentence :

The State Transport Corporation has ……… a loss of Rs. 5 crore this year.

(A)  obtained

(B)  derived

(C)  incurred

(D)  formulated

Answer: (C)

114. About 50% of the total silk textile produced in India is at

(A)  Uttar Pradesh

(B)  Karnataka

(C)  West Bengal

(D)  Jammu & Kashmir

Answer: (B)

115. How many items are there in the Concurrent List?

(A)  52 items

(B)  80 items

(C)  90 items

(D)  66 items

Answer: (A)

116. The Governor holds office

(A)  for a term of five years

(B)  during a pleasure of the President

(C)  during the pleasure of the chief minister

(D)  as long as he enjoys the confidence of the State Legislature

Answer: (B)

117. All acids essentially contain

(A)  Oxygen

(B)  Chlorine

(C)  Sulphur

(D)  Hydrogen

Answer: (D)

118. Excessive intake of polished rice causes deficiency of

(A)  Vitamin A

(B)  Vitamin B

(C)  Vitamin D

(D)  Vitamin K

Answer: (B)

119. Who was the first Muslim ruler of Delhi ?

(A)  Iltutmish

(B)  Allauddin Khalji

(C)  Qutbuddin Albak

(D)  Mahmud of Ghazni

Answer: (C)

120. Author of ‘Wings of Fire’ is

(A)  Sonia Gandhi

(B)  APJ. Abdul Kalam

(C)  K. R. Narayanan

(D)  P. V. Narasimha Rao

Answer: (B)

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