Digital Communications

Noise

Question 1
Marks : +2 | -2
Pass Ratio : 100%
Thermal noise is
Energy signal
Power signal
Energy & Power signal
None of the mentioned
Explanation:
Thermal noise is considered as power signal as it has infinite energy.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
Eigen functions are not orthogonal.
True
False
Explanation:
An important property of eigen function is that they are orthogonal.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
SQNR can be improved by _______ sampling rate.
Increasing
Decreasing
Does not depend
None of the mentioned
Explanation:
SQNR can be improved by increasing the sampling rate.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
Noise has
Infinite energy
Infinite power
Infinite energy & power
None of the mentioned
Explanation:
Noise has infinite energy signal.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
Shot noise is avoidable when current is
Zero
One
Infinity
None of the mentioned
Explanation:
Shot noise is avoidable only when the current is zero.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
Which occurs due to equilibrium fluctuations?
Thermal noise
Johnson noise
Thermal & Johnson noise
None of the mentioned
Explanation:
Thermal noise occurs due to equilibrium fluctuations. This noise is also called as Johnson noise.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
Capacity of the channel can be increased by reducing in band noise power.
True
False
Explanation:
Capacity of a channel can be increased by reducing the in band noise power.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
Which has the same power spectral density?
White noise
Brown noise
White & Brown noise
None of the mentioned
Explanation:
White noise has same power spectral density where as it decreases in case of brown noise.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
Which consists of less ISI?
Nyquist filter
Raised cosine filter
Nyquist & Raised cosine filter
None of the mentioned
Explanation:
Raised cosine filter results in less ISI than Nyquist filter.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
Capacity of a channel can be increased by
Increasing channel bandwidth
Increasing signal power
Increasing channel bandwidth &signal power
None of the mentioned
Explanation:
Capacity of a channel can be increased by increasing channel bandwidth and also by increasing signal power.