Analog Communication System MCQs

Question 1

In a ratio detector

Accepted Answer

the linearity is worse than in a phase discriminator

Answer

the circuit is the same as in a discriminator except that the diode are reversed

Answer

the output is twice that obtainable from a similar phase discriminator

Answer

stabilization against signal strength variations is provided

Question 2

A heterodyne frequencychanger is called a

Accepted Answer

mixer

Answer

frequency translator

Answer

modulator

Answer

none of the above

Question 3

Padders are providedin a radio receiver

Accepted Answer

to improve tracking

Answer

to improve sentsitivity

Answer

for fine tuning

Answer

for reducing noise

Question 4

1n AM receiver the oscillator frequency is always

Accepted Answer

higher than signal frequency

Answer

equal to 455 kHz

Answer

lower than signal frequency

Answer

equal to signal frequency

Question 5

Fidelity in a communication receiver is provided by

Accepted Answer

audio stage

Answer

degtector stage

Answer

mixer stage

Answer

none of the above

Question 6

Which of the following statements is correct? Sensitivity and selectivity of a heterodyne receiver

Accepted Answer

is better than a tuned radio frequency (TRF) receiver

Answer

is pooerer than TRF receiver

Answer

sensitivity is better in heterodyne receiver, selectivity is better in TRF receiver

Answer

sensisitivity and selectivity is the same in both

Question 7

Which of the following is an indirect method of generating FM?

Accepted Answer

Answer

Varactor diode modulation

Answer

Reactive FM modulator Reactance BJT modulator

Answer

(e) Armstrong modulation

Question 8

The highest modulation frequency typically used in FM broadcase is

Accepted Answer

15 kHz

Answer

10 kHz

Answer

20 kHz

Answer

25 kHz

Question 9

In radio receiver, squelch circuit is used to

Accepted Answer

cut off and to amplify between stations

Answer

reduce RF interference

Answer

catch weak signals

Answer

reduce noise