Digital Communications

Digital Communication System

Question 1
Marks : +2 | -2
Pass Ratio : 100%
What conditions must be fulfilled in a good digital communication system?
High data rate
High fidelity
Low transmit power
All of the mentioned
Explanation:
Some of the conditions which must be satisfied in a digital communication system are high data rate, high fidelity, low bandwidth, low transmit power and low transmitter and receiver complexity.
Question 2
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 3
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 4
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 5
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 6
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 7
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 8
Marks : +2 | -2
Pass Ratio : 100%
The basic transmission-reception system is a ______ system.
Two block system
Three block system
Four block system
None of the mentioned
Explanation:
The basic transmission-reception consists of three blocks – transmitter, transmission medium, receiver.
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%
Transmission media used for medium frequency band are
Coaxial cable
Copper cable
Optical fiber
All of the mentioned
Explanation:
For medium frequency band communication air and copper cable can only be used as a transmission medium.