Analog Communication System MCQs

Question 1

In a low level amplitude modulation system, the amplifier following the modulated stage must be

Accepted Answer

a linear device

Answer

a class-C amplifier

Answer

a non-linear device

Answer

a harmonic device

Question 2

One can provide two or more voice circuits on the same carrier by using

Accepted Answer

ISB systems

Answer

DSB-SC

Answer

SSB with pilot carrier

Answer

SSB-BC system

Question 3

100 percent modulation is produced in AM when carrier

Accepted Answer

amplitude equal signal amplitude

Answer

amplitude exceeds signal amplitude

Answer

frequency equals signal frequency

Answer

frequency exceeds signal frequency

Question 4

In RF amplifiers neutralisation is used to

Accepted Answer

stop oscillations

Answer

improve selectivity

Answer

increase bandwith

Answer

all of the above

Question 5

An amplitude modulated wave is

Accepted Answer

the sum of the carrier and the modulating wave

Answer

the product of the carrier and the modulating wave

Answer

sum of the carrier and its product with modulating signal

Answer

the difference between the carrier and the modulating wave

Question 6

The modulation index of an amplitude modulated wave is changed from 0 to 1. The transmitted power is

Accepted Answer

increased by 50 percent

Answer

doubled

Answer

halved

Answer

unchanged

Question 7

A SSB (Single-side band) signal contains 3 kW. The power content of the carrier is

Accepted Answer

0 kW

Answer

1 kW

Answer

2 kW

Answer

3 kW

Question 8

If a signal band limited to fm is sampled at a rate less than 2 fm, the reconstructed signal will

Accepted Answer

be distorted

Answer

be samller in amplitude

Answer

have higher frequencies suppressed

Answer

none of the above

Question 9

A transistor is basically an amplifying device for

Accepted Answer

current

Answer

voltage

Answer

power

Answer

none of the above