1. Noise has
a) Infinite energy
b) Infinite power
c) Infinite energy & power
d) None of the mentioned
Explanation: Noise has infinite energy signal.
2. Thermal noise is
a) Energy signal
b) Power signal
c) Energy & Power signal
d) None of the mentioned
Explanation: Thermal noise is considered as power signal as it has infinite energy.
3. The maximum likelihood function is
a) Positive
b) Negative
c) Any of the mentioned
d) None of the mentioned
Explanation: The maximum likelihood function is always positive.
4. Matched filtering operation includes
a) Spectral phase matching
b) Spectral amplitude matching
c) Spectral phase & amplitude matching
d) None of the mentioned
Explanation: Matched filtering includes two operations – spectral amplitude matching and spectral phase matching.
5. Which consists of less ISI?
a) Nyquist filter
b) Raised cosine filter
c) Nyquist & Raised cosine filter
d) None of the mentioned
Explanation: Raised cosine filter results in less ISI than Nyquist filter.
6. Matched filter is
a) Linear
b) Non linear
c) Linear & Non linear
d) None of the mentioned
Explanation: Matched filter is a linear filter.
7. Digital communication is _______ to environmental changes?
a) More sensitive
b) Less sensitive
c) Does not depend
d) None of the mentioned
Explanation: Digital communication is less sensitive to environmental changes like temperature etc.
8. Advantages of digital communication are
a) Easy multiplexing
b) Easy processing
c) Reliable
d) All of the mentioned
Explanation: Digital communication is a very reliable communication. It is easy for multiplexing, easy for signalling and processing etc.
9. What is necessary for digital communication?
a) Precision timing
b) Frame synchronization
c) Character synchronization
d) 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.
10. What are the disadvantages of digital communication?
a) Needs more bandwidth
b) Is more complex
c) Needs more bandwidth & Is more complex
d) 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.