A`p-n-p` transistor is used in common-emitter mode in an amplifier circuuit. A change of `40muA` in the base current brings a change of `2mA` in collector current and `0.04V` in base-emitter volatage. Find the
(a) input resistance `r_(i)` and
(b) the base current amplification factor `(beta)`.
(c ) if a load of `6kOmega` is used, then also find the voltage gain of the amplifier.

Options

A. `1000 Omega, 50`
B. `2000 Omega, 40`
C. `5000 Omega, 20`
D. none of these

Answer

A

Explanation

`R_(i)=(V_("be"))/(I_(b))`
`=(0.04)/(40xx10^(-6))=1000 Omega`
`beta=(I_(c))/(I_(b))=(2xx10^(-3))/(40xx10^(-6))=50`