An amplifier draws 1.8 W from its dc power supply and delivers 250 mW to its load. What is the efficiency of the amplifier?
A) 45%
B) 13.9%
C) 87.8%
D) 12.2%

Question

Quizplus · Accepted Answer

The efficiency of an amplifier is calculated as the output power divided by the input power, multiplied by 100 to get a percentage. Here, the output power is 250 mW (or 0.25 W) and the input power is 1.8 W. Thus, efficiency = (0.25 / 1.8) * 100 = 13.9%.

An Amplifier Draws 1