The percentage increase in signal power of a carrier amplitude

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The percentage increase in signal power of a carrier amplitude modulated 100% by a square wave—

1. 50%
2. 100%
3. 200%
4. None of these

Correct Option: B

Let the given square wave looks like as shown below.
Since the average value of square wave i.e.m(t) = 1 and, on 100% modulation the amplitude of the carrier will be twice for half the time and zero for the other half time. Now, P_t = P_c [1+ m²(t)] = P_c [1 + 1] = 2P_c
Percentage increase in power

=	2 P_c − P_c	×100 = 100
	P_c