Digital Communications

Digital Communication System

Question 1
Marks : +2 | -2
Pass Ratio : 100%
What are the main features of a receiver?
Synchronization
Multiple parallel receiver chain
Synchronization & Multiple parallel receiver chain
None of the mentioned
Explanation:
The main features of a receiver which increases its complexity are synchronization of carrier, phase, and timing and multiple parallel receiver chain.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
Ground wave communication occurs in
Low frequency band
Medium frequency band
Low & Medium frequency band
None of the mentioned
Explanation:
Ground wave communication can take place in both low frequency and medium frequency bands.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
Wired channels are
Lossy
Lossless
Lossy & Lossless
None of the mentioned
Explanation:
Wired channels are lossy channels.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
Which is practically realizable?
A train of pulses
Impulse train
All of the mentioned
None of the mentioned
Explanation:
A train of pulses with narrow bandwidth is realizable than the impulse train.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
Matched filter technique is used to
Increase SNR
Decrease SNR
SNR is not affected
None of the mentioned
Explanation:
Matched filter technique is a demodulation process used to increase SNR.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
Modulation channel does not accept an analog input signal.
True
False
Explanation:
Modulation channel accepts analog signal as input and delivers another version of modulated signal as analog waveform.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
Which corrects the sampling time problem in a digital system?
Interpolator
Decimator
Equalizer
Filter
Explanation:
Interpolator corrects the sampling time problem using discrete time processing.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
A signal can be recovered from its sample by using
Low pass filter
High pass filter
Band pass filter
Band stop filter
Explanation:
A signal can be recovered from its sampled version by using an ideal low pass filter.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
In flat top sampling scheme, ______ is kept constant after sampling.
Amplitude
Phase
Frequency
Time period
Explanation:
In flat top sampling scheme, the amplitude is kept constant after sampling.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
What are the main features of a transmitter?
Higher clock speed
Linear power amplifier
Directional antennas
All of the mentioned
Explanation:
Some of the main features which make the transmitter complex are higher clock speed, higher transmit power, directional antennas and need for a linear amplifier.