M-ary Modulation and Amplifiers

Question 1
Marks : +2 | -2
Pass Ratio : 100%
Which generates high distortion?
Class A
Class B
Class C
Class AB
Explanation:
Class C amplifiers generate high distortion and it is closer to switch than an amplifier.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
Class B linear amplifiers have maximum power efficiency of
50%
75%
78.5%
None of the mentioned
Explanation:
Class B linear amplifiers have maximum power efficiency of 78.5%.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
Which has the maximum power efficiency?
Class A
Class B
Class C
Class AB
Explanation:
Class C has the maximum power efficiency when compared to the other linear amplifiers.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
In M-ary FSK as M tends to infinity, probability of error tends to
Infinity
Unity
Zero
None of the mentioned
Explanation:
In M-ary FSK as M tends to infinity, probability of error becomes zero.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
Which has 50% maximum power efficiency?
Class A
Class B
Class AB
None of the mentioned
Explanation:
Class A amplifiers have 50% maximum power efficiency.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
For non coherent reception of PSK _____ is used.
Differential encoding
Decoding
Differential encoding & Decoding
None of the mentioned
Explanation:
For non coherent reception of PSK, differential encoding is used at the transmitter and decoding is used at the receiver.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
Which modulation technique have the same bit and symbol error probability?
BPSK
DPSK
OOK
All of the mentioned
Explanation:
BPSK, DPSK, OOK and non coherent FSK have same bit and symbol error probability.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
In M-ary FSK, as M increases error
Increases
Decreases
Does not get effected
Cannot be determined
Explanation:
In M-ary FSK as M increases error decreases.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
Free space in idealization which consists
Transmitter
Receiver
Transmitter & Receiver
None of the mentioned
Explanation:
Free space is an idealization that consists of only transmitter and receiver.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
An amplifier uses ______ to take input signal.
DC power
AC power
DC & AC power
None of the mentioned
Explanation:
An amplifier uses DC power to take an input signal and increase its amplitude at the output.