Q. A common emitter amplifier has a voltage gain of 50, an input impedance of 100Ω and an output impedance of 200Ω. The power gain of the amplifier is
A) 1000
B) 1250
C) 100
D) 500
Explanation
[Solution from source] Voltage gain Av = β(Rout/Rin), so β = 50 × 100/200 = 25. Power gain = Av × β = 50 × 25 = 1250. 1000 or 500 come from misusing the impedance ratio. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.