A transistor with `alpha=0.98` is operated in common emitter circuit with a load resistance of `5" k"Omega`. If the dynamic resistance of the emitter junction is `70Omega`, the voltage gain and power gain will be

Options

A. `3500, 1.715xx10^(5)`
B. `4000, 2.715xx10^(5)`
C. `2500, 1.215xx10^(5)`
D. None of these

Answer

A

Explanation

As, `beta =(alpha)/(1-alpha)=(0.98)/(1-0.98)`
`=(0.98)/(0.02)=49`
Voltage gain
`A_(v)=beta(R_(2))/(R_(1))=(49xx5xx10^(3))/(70)=3500`
Power gain
= voltage `xx` current gain
`=3500xx49`
`=1.715xx10^(5)`