Question

A common emitter amplifier has a voltage gain of 50, an input impedance of 100 and an output impedance of 200. The power gain of the amplifier is

• A. 1000
• B. 1250
• C. 500
• D. 250

Answer 1

The correct option is B 1250

Let the voltage of input be $v$

Given that the voltage gain is $50$ , so the voltage of output is $50v$

The input impedence is $100$ and the output impedence is $200$

The power gain of the amplifier is $(\frac{50v}{v}{)}^2\times \frac{100}{200}=1250$

Therefore the correct option is $B$