Digital Communication System MCQs

Question 1

Teleprinter code is unit code.

Accepted Answer

7 -5-

Answer

1

Answer

4

Answer

6

Question 2

Which of the following TV systems is adopted in India?

Accepted Answer

PAL system

Answer

NTSC system

Answer

CCTv system

Answer

None of the above

Question 3

In communication receivers the fidelity is provided by

Accepted Answer

audio stage

Answer

detector range

Answer

mixer stage

Answer

all of the above

Question 4

Due to which of the following reasons radar detection is limited to line of sight?

Accepted Answer

Curvature of the earth

Answer

Short wavelengths are used

Answer

Long wavelengths are used

Answer

the waves are not reflected by the ionosphere

Question 5

In morse code the spacing between the elements is

Accepted Answer

1 dot

Answer

3 dots

Answer

6 dots

Answer

9 dots

Question 6

According to Hartley's law

Accepted Answer

the maximum rate of information depends on the channel bandwidth

Answer

only binary codes may be used

Answer

the maximum rate of information transmission depends on the depth of modulation

Answer

redundancy is essential

Question 7

A modulator is a device to

Accepted Answer

Answer

extract information from the carrier

Answer

amplify the audio frequency signal separate two frequencies

Answer

(e) impress the information on to a radio frequency carrier

Question 8

PDM is generated by using

Accepted Answer

Monostable vibrator

Answer

JK flip-flop

Answer

Schmitt trigger

Answer

Free running multivibrator

Question 9

To modulate PCM, it is first converted into

Accepted Answer

PAM

Answer

PDM

Answer

PPM

Answer

PWM