This set of Digital Communications Multiple Choice Questions & Answers (MCQs) focuses on “Digital Communication Signal Processing”.
1. Which circuit is called as regenerative repeaters?
a) Analog circuits
b) Digital circuits
c) Amplifiers
d) A/D converters
View Answer
Explanation: The main advantage of digital communication is that the signals can be reproduced easily. Thus digital circuits are called as regenerative repeaters.
2. What are the advantages of digital circuits?
a) Less noise
b) Less interference
c) More flexible
d) All of the mentioned
View Answer
Explanation: Digital circuits are less subject to noise, distortion and interference as it works on digital pulses and also the pulses can be regenerated.
3. How many different combinations can be made from a n bit value?
a) 2(n+1)
b) 2(n)
c) 2(n)+1
d) None of the mentioned
View Answer
Explanation: 2(n) different combinations can be made from n bit value. For example, from 2 bit value 22 different combinations-00,01,10,11 can be made.
4. How many bytes does a gigabyte have?
a) 1 million bytes
b) 10 million bytes
c) 1 billion bytes
d) 10 billion bytes
View Answer
Explanation: One gigabyte has 1 billion bytes.
5. What is the ASCII value of space?
a) 32
b) 48
c) 96
d) 65
View Answer
Explanation: The ASCII value of space is 32 and ASCII value of 0 is 48.
6. Which block or device does the data compression?
a) Channel encoder
b) Source encoder
c) Modulator
d) None of the mentioned
View Answer
Explanation: Source encoder converts the digital or analog signal to a sequence of binary digits. This process is called as source encoding or compression.
7. What is the code rate?
a) k/n
b) n/k
c) All of the mentioned
d) None of the mentioned
View Answer
Explanation: Here n is the total bits of sequence and k bits are mapped. Amount of redundancy introduced is given by n/k and its reciprocal is the code rate.
8. Pulse shaping is done by which block or system?
a) Encoder
b) Baseband modulator
c) Pulse code modulator
d) Demodulator
View Answer
Explanation: Pulse code modulator does filtering process to build pulses that occupy more than one bit time.
9. Equalizer is used for?
a) Filtering
b) Diminish distortion
c) All of the mentioned
d) None of the mentioned
View Answer
Explanation: Equalizer is used as a filtering option and also diminishes or reduces the distortion.
10. Source coding block is used for?
a) Compressing
b) Digitizing
c) A/D conversion
d) All of the mentioned
View Answer
Explanation: Source encoding does all these processes-compression, digitizing the signal and performs analog to digital conversion.
11. Which measurement considers phase as an important parameter?
a) Coherent
b) Non-coherent
c) All of the mentioned
d) None of the mentioned
View Answer
Explanation: Coherent measurement considers phase as an important parameter.
12. The size of the alphabet M in symbol is calculated as?
a) 2(k+1)
b) 2k
c) 2(k-1)
d) 1+2k
View Answer
Explanation: The size of the alphabet is calculated using 2^k where k is the number of bits in the symbol.
Sanfoundry Global Education & Learning Series – Digital Communications.
To practice all areas of Digital Communications, here is complete set of 1000+ Multiple Choice Questions and Answers.
If you find a mistake in question / option / answer, kindly take a screenshot and email to [email protected]
