Analog Communication System MCQs

Question 1

AGC voltage is applied to the stages which are

Accepted Answer

before the detector stage

Answer

after the detector stage

Answer

either before or after the detector stage

Answer

none of the above

Question 2

Which one of the following is not necessarily an advantage of the phase cancellation method of obtaining SSB over the filter method?

Accepted Answer

there are more balanced modulators; therefore the carrier is suppressed better.

Answer

It is possible to generate SSB at any frequency

Answer

SSB with lower audio frequencies present can be generated

Answer

switching from one side band to the other is simpler

Question 3

A pilot carrier in SSB is provided

Accepted Answer

as an auxiliary source of power

Answer

to reduce noise

Answer

for reducing power consumption

Answer

for frequency stabilisation

Question 4

The upper and lower side frequencies for 3 kHz audio modulation with a 27 MHz carrier frequency will be

Accepted Answer

27.003 and 26.997 MHz

Answer

30 and 24 MHz

Answer

27.3 and 26.7 MHz

Answer

27.03 and 26.97 MHz

Question 5

The unit of modulation index is

Accepted Answer

no unit

Answer

Hertz

Answer

(Hz)-1

Answer

(Hz)-2

Question 6

The type of emission of the standard AM radio broadcast band is

Accepted Answer

A3

Answer

A 5C

Answer

AO

Answer

F3

Question 7

In FM the carrier deviation is determined bY

Accepted Answer

modulating voltage

Answer

frequency

Answer

either of the above

Answer

none of the above

Question 8

The percentage of modulation for 45 kHz deviation in the FM broadcast band will be

Accepted Answer

60%

Answer

30%

Answer

40 W

Answer

90%

Question 9

A FM wave is represented by e = 12 sin (6 x 108t + 5.5 sin 1250 t) The carrier frequency is

Accepted Answer

95.5 Wiz

Answer

66 MHz

Answer

125 MHz

Answer

166 MHz