In a $NPN$ transistor,the collector current is $24 \, mA$. If $80\%$ of electrons reach the collector,what is the base current in $mA$?

Consider an amplifier circuit wherein a transistor is used in common emitter mode. The change in collector current and base current respectively are $4 mA$ and $20 \mu A$ when a signal of $40 mV$ is added to the base-emitter voltage. If the load resistance is $10 k\Omega$, then the power gain in the circuit is:

In case of a bipolar transistor, $\beta = 45$. The potential drop across the collector resistance of $1 \ k\Omega$ is $5 \ V$. The base current is approximately: (in $\mu A$)

$A$ $CE$ amplifier has a voltage gain of $G$. The transistor used has a transconductance of $0.03 \ mho$ and a current gain of $25$. If this transistor is replaced by another transistor with a transconductance of $0.02 \ mho$ and a current gain of $20$,the new voltage gain will be ........

For a common emitter transistor,if $\frac{I_{C}}{I_{E}}=0.95$,then the current gain is

Which region is the least doped in a transistor?