Digital Communications

Digital Communication

Question 1
Marks : +2 | -2
Pass Ratio : 100%
Synchronization available in digital communication are
Symbol synchronization
Frame synchronization
Carrier synchronization
All of the mentioned
Explanation:
The synchronization techniques available in digital communication are symbol synchronization, frame synchronization and carrier synchronization.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
Advantages of digital communication are
Easy multiplexing
Easy processing
Reliable
All of the mentioned
Explanation:
Digital communication is a very reliable communication. It is easy for multiplexing, easy for signalling and processing etc.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
The interval of frequencies outside which the spectrum is zero is called as ________
null to null bandwidth
normalized bandwidth
absolute bandwidth
none of the mentioned
Explanation:
The measure of frequencies outside which spectrum is zero is called as absolute bandwidth. It is usually infinite.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
The attenuation level in bounded power spectral density is
35
50
35 & 50
none of the mentioned
Explanation:
Bounded power spectral density is the bandwidth outside which the spectrum must have fallen to a stated level below that found at the band center.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
Digital system includes
Better encryption algorithm
Difficult data multiplexing
All of the mentioned
None of the mentioned
Explanation:
Digital system has an advantage of better encryption algorithm, easier data multiplexing and more reliability.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
Which system uses digital transmission?
ISDN
LANs
ISDN & LANs
None of the mentioned
Explanation:
Though the signal type is analog or digital, the transmission takes place in the digital domain in ISDN and LANs.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
What are the disadvantages of digital communication?
Needs more bandwidth
Is more complex
Needs more bandwidth & Is more complex
None of the mentioned
Explanation:
Digital communication needs more bandwidth, has higher complexity and little performance degradation occurs during analog to digital conversion and vice versa.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
What is necessary for digital communication?
Precision timing
Frame synchronization
Character synchronization
All of the mentioned
Explanation:
Bit, character, frame synchronization and precision timing is necessary for digital communication. This is considered as a disadvantage of digital communication.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
Digital communication is _______ to environmental changes?
Less sensitive
More sensitive
Does not depend
None of the mentioned
Explanation:
Digital communication is less sensitive to environmental changes like temperature etc.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
Examples of digital communication are
ISDN
Modems
Classical telephony
All of the mentioned
Explanation:
Some of the examples of digital communication systems are classical telephony, ISDN, Modems, LANs, PCM TDM etc.