Questions and answers for exam Preparation

MCQs

Total Questions : 260 | Page 1 of 26 pages

Question 1. In a PCM system, the quantisation noise depends upon.

the number of quantisation levels only
the smapling rate only
both the sampling rate and the number of quantisation levels
none of the above is correct

Discuss Question

Answer: Option A. -> the number of quantisation levels only

Question 2. One can provide two or more voice circuit on the same carrier by using

SSB-SC system
ISB system
SSB with pilot carrier
DSB-SC

Discuss Question

Answer: Option B. -> ISB system

Question 3. The coupling used in Stoneman transmission bridge is

resistive
capacitive
inductive
a combination of all the above

Discuss Question

Answer: Option B. -> capacitive

Question 4. If in a radio receiver, RF signal has a frequency of 800 kHz and local oscillator that of 1000 kHz, then at the output of the mixer, the frequencies found would be kHz.

800 and 1000
200, 800, 1000, 1800
only 200
only 1800

Discuss Question

Answer: Option B. -> 200, 800, 1000, 1800

Question 5. A pulse train has a pulse-repetition frequency of 25,000 pulses per second and pulses have a duration of 4 ps. The mark-to-phase ratio is

1 : 10
I : 25,000
1 : 9
1 : 1

Discuss Question

Answer: Option A. -> 1 : 10

Question 6. Complete the undergiven matching panel by utilizing the table listing numbered frequencies and lettered frequency bands. Frequencies-Frequency band,1.200 MHz-A. VLF,2. 20 kHz-B. MF,3. 10 MHz-C. VHF,4. 500 kHz-D. SHF,5. 500 MHz-E. HF,6. 20 GHz-F. UHF

f (x) - 271r; c7-
f (x) = 27[7(7 E_(,__m)
(x?m)2/2 o-2
2/2 cr21?(x?m)2/2 cs2

Discuss Question

Answer: Option C. -> (x?m)2/2 o-2

Question 7. Which of the following statement is not correct? Interference between two or more transmitted signals can be avoided by

transmitting each signal at a different frequency level along the same pair of conductors
using separate pairs of conductors for each signal
transmitting each signal at a different amplitude along same pair of conductors
sampling the signals at a sampling frequency of 8 kHz and transmitting the samples of signals, taken in turn, along the same pair of conductors

Discuss Question

Answer: Option C. -> transmitting each signal at a different amplitude along same pair of conductors

Question 8. Regarding two-way communication operation called duplex working, which statement is wrong?

requires different frequencies at the sending and receiving ends
makes maximum use of the available bandwidth
makes communication as normal as a telephone conversation
permits speech in two directions

Discuss Question

Answer: Option B. -> makes maximum use of the available bandwidth

Question 9. . The main advantage of PCM system is lower

bandwidth
power
noise
none of the above

Discuss Question

Answer: Option C. -> noise

Question 10. . Regarding use of synchronous system in data transmission which statement is wrong?

theyestablish synchronism at the beginning of a message
they are widely used for high data rates where data is in the form of a continuous stream
they do not require large number of extra bits per code
they are ideal for coping with data sources which are sporadic in nature such as a human being generating data on a teletypewriter

Discuss Question

Answer: Option D. -> they are ideal for coping with data sources which are sporadic in nature such as a human being generating data on a teletypewriter