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

Options

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

Answer

A

Explanation

Voltage gain `(A_V) = (V_(out))/(V_("in"))= I_(out)/(I_("in")) xx R_(out)/R_("in)`
`A_V = (2xx 10^(-3))/(40xx10^(-6)) xx(4xx10^3)/100 = 2xx 1000=2000`