Digital Communications

Sampling and Quantization

Question 1
Marks : +2 | -2
Pass Ratio : 100%
Which requires interpolation filtering?
Up-sampler
D to A converter
Up-sampler & D to A converter
None of the mentioned
Explanation:
Up-sampler and D to A conversion need interpolation filtering.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
Different cases of sampling include
Ideal impulse sampling
Flat-topped sampling
Sampling with rectangular pulses
All of the mentioned
Explanation:
The three cases of sampling are ideal impulse sampling, sampling with rectangular pulses and flat topped sampling.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
A to D conversion process uses
Sampler
Quantizer
Sampler & Quantizer
None of the mentioned
Explanation:
A to D conversion process requires both sampler and quantizer.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
The quantization will be finer when
Smaller the number of discrete amplitudes
Larger the number of discrete amplitudes
Does not depend on amplitudes
None of the mentioned
Explanation:
Larger the number of discrete amplitudes, finer will be the quantization.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
Which process requires low pass filter?
Up-sampling
Down-sampling
Up-sampling & Down-sampling
None of the mentioned
Explanation:
Up-sampling requires low pass filter after increasing the data rate and down-sampling requires low pass filter before decimation.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
Delay element in delta modulation acts as
First order predictor
Second order predictor
Third order predictor
Fourth order predictor
Explanation:
Delay element act as first order predictor.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
Transmitted pulse becomes distorted due to
Ideal transmission characteristic
Non ideal transmission characteristic
All of the mentioned
None of the mentioned
Explanation:
A transmitted pulse gradually becomes distorted due to non ideal transmission characteristic of the channel.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
The signal can be reconstructed
At Nyquist rate
Above Nyquist rate
At & above the Nyquist rate
None of the mentioned
Explanation:
The signal can be reconstructed from the sampled version at or above Nyquist rate using simple low pass filtering.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
To avoid aliasing
Reduce the bandwidth
Cut out high frequency
Reduce the bandwidth & Cut out high frequency
None of the mentioned
Explanation:
To avoid aliasing bandwidth should be reduced and high frequency should be cut out.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
Shot noise occurs in
Transistors
Valves
Transistors & Valves
None of the mentioned
Explanation:
Shot noise occurs in both valves and transistors.