51. The total power of an AM -modulated carrier wave is 1160 𝑊 while that of each side-band is 80 𝑊. The modulation index is
(a) 0.08
(b) 0.2
(c) 0.4
(d) 0.81

Answer: (c)

52. The intermediate frequency IF in standard AM receiver is:
(a) 455 Hz
(b) 455 kHz
(c) 4.55 MHz
(d) 45.5 MHz

Answer: (b)

53. A complex band pass signal has bandwidth of 500 kHz and the lowest frequency of 200 kHz, then the Nyquist minimum sampling rate will be
(a) 14,00,000 Samples / sec
(b) 10,00,000 Samples / sec
(c) 7,00,000 Samples / sec
(d) 4,00,000 Samples / sec

Answer: (a)

54. The chemical composition of a quartz crystal is
(a) Germanium oxide
(b) Silicon dioxide
(c) Sodium silicate
(d) Mixture of Germanium oxide and Sodium silicate

Answer: (b)

55. An object falling through air will fall faster than the one falling through water, because:
(a) Air has much less fluid resistance than water
(b) Weight of the object in water is more than that in air
(c) Air has much more friction than water
(d) Size of the object in water is more than that in air

Answer: (a)

56. For which of the following regions, a transistor as a switch will be stable?
(a) Saturation and active
(b) Active and cutoff
(c) Cutoff and saturation
(d) Active and saturation

Answer: (c)

57. Which of the following is a current controlled device?
(a) JEET
(b) MOSFET
(c) BJT
(d) Zener diode

Answer: (c)

58. What is the value of an inductance when an inductor filter is connected to a full wave rectifier operating at 60 Hz for providing a dc output voltage with 4 % ripple at 100 Ω load?
(a) 1.5625 𝐻
(b) 2.3525 𝐻
(c) 1.3525 𝐻
(d) 2.5625 𝐻

Answer: (a)

59. An amplifier of gain 1000 has a gain-change of 20 % due to temperature variation. If a negative feed-back of 0.1 is introduced into the above amplifier, the change in gain of the feedback amplifier due to the temperature variation would be
(a) 0.01 %
(b) 0.2 %
(c) 5 %
(d) 7.5 %

Answer: (b)

60. Consider the Unix shell command:
Sort studentmarks | more

It means:
(a) Use the ‘sort’ command as a pipe for file ‘students’, and filter to command ‘more’
(b) Use the ‘sort’ filter on file ‘studentmarks’, and pipe to the command ‘more’
(c) Output the sorted ‘studentmarks’, to file ‘more’
(d) Request more input for file ‘studentmarks’ in order to sort it

Answer: (b)