Digital Communications

Digital Communication System

Question 1
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.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
The equivalent temperature in a receiver design must be kept
Low
High
Does not affect the receiver
None of the mentioned
Explanation:
The equivalent temperature is the function of the receiver design and it must be always kept low.
Question 3
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 4
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 5
Marks : +2 | -2
Pass Ratio : 100%
Modulation channel consists of
Amplifier
Signal processing units
Amplifier & Signal processing units
None of the mentioned
Explanation:
When information is transmitted through large distance it must be amplified. Modulation channel consists of an amplifier and other signal processing units.
Question 6
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 7
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 8
Marks : +2 | -2
Pass Ratio : 100%
Sampling theorem is used for converting
Continuous time signal to discrete
Discrete to continuous time signal
Continuous time signal to discrete & vice versa
None of the mentioned
Explanation:
Sampling theorem is used for converting continuous time signal to discrete type signal and vice versa.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
Transmission media used in low frequency band are
Air
Water
Copper cable
All of the mentioned
Explanation:
Air, water and copper cable can be used as transmission media in low frequency band communication.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
Wired channels are
Lossy
Lossless
Lossy & Lossless
None of the mentioned
Explanation:
Wired channels are lossy channels.