An intelligence signal is amplified by a 65% efficient amplifier before being combined with a 250W carrier to generate an AM signal. If it is desired to operate at 100% modulation, what must be the dc input power to the final intelligence signal amplifier?
A) 192.3W
B) 162.5W
C) 83.3W
D) 384.6W

Question

Quizplus · Accepted Answer

To achieve 100% modulation, the power of the intelligence signal must be equal to half of the carrier power. The carrier power is 250W, so the intelligence power needed is 125W. Given the amplifier is 65% efficient, the input power required is 125W / 0.65 = 192.3W.

An Intelligence Signal Is Amplified by a 65% Efficient Amplifier