BSNL Placement Papers
Company: Bharat Sanchar Nigam Ltd
Bharat Sanchar Nigam Ltd (BSNL)
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 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) 30KHz
c) 10KHz
d) 40KHz
54. 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
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 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
59. The output Qn is 1 in a JK flip flop 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) a debouncer circuit
d) a-D- latch
63. Number of nybbles 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. 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
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 Geosychronous 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
68. Radio Broadcasting is an example of ?
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) A Schmitt trigger followed by a LPF
c) A differentiator followed by a LPF
d) A clipper circuit by a LPF
70. In an 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 varoctor diode in generation of modulated segial be-
a) FM generation only
b) 100AM generation only
c) PM generation only
d) both PM and AM generation
73. 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
74. 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 sawtooth current
75. Band width of microwaves is-
a) 1GHz -103 GHz
b) 1GHz ?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) bath magnetic & electric lines are is direction of propagation
d) neither magnetic nor electric lines in direction of propagation
77. Signal transmission in sky wave propagation is due to ?
a) Reforction of wave
b) Reflection of wave
c) Pierus through Inosphere
d) None
78. According to Barkhausen Criterion Phase shift of signal should be ?
a) 600
b) 900
c) 1800
d) 3600
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 signal to noise ratio X o/p signal to noise ratio
b) i/p S/N Ratio / O/P S/N Ratio
c) i/p S/N Ratio / O/P S/N Ratio X 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 G(S) = 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 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 in coming 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. The son seems to have ——– from his father a somewhat gloomy and moody manner-
a) washed
b) inherited
c) admired
d) attempt
BSNL Placement Papers
About BSNL
Bharat Sanchar Nigam Limited d/b/a BSNL is a government owned telecommunications service provider headquartered in New Delhi, India. It is under the ownership of Department of Telecommunications, Ministry of Communications, Government of India. It was incorporated on 15 September 2000 by the Government of India. visit offical website of BSNL for more details.