The input resistance of a silicon transistor is `100Omega` base current is changed by `40muA` which results in a change in collector current by `2mA`. This transistor is used as a common emitter amplifier with a load resistance of `4kOmega`. The voltage gain of the amplifier is

Options

A. 2000
B. 3000
C. 4000
D. 1000

Answer

A

Explanation

We know voltage gain is, `A_(V)=beta(R_(L))/(R_(i))`
On putting given values,
`A_(V)=(2xx10^(-3))/(40xx10^(-6))xx(4xx10^(3))/(100) " " [because beta=(DeltaI_(C))/(DeltaI_(B))]`
`A_(V)=2000`