An $n-p-n$ transistor power amplifier in $C-E$ configuration gives

When an $n-p-n$ junction transistor is used as an amplifier in common emitter mode,

$A$ transistor is operating in the active mode. $v_1$ is the potential barrier across the base-emitter junction and $v_2$ is the potential barrier across the collector-base junction. $b_1$ is the width of the depletion layer of the base-emitter junction and $b_2$ is the width of the collector-base junction.

In an $NPN$ transistor circuit,the collector current is $10 \ mA$. If $95\%$ of the electrons emitted reach the collector,what is the base current in $mA$?

An $n-p-n$ transistor with current gain $\beta=100$ in common emitter configuration is shown in the figure. The output voltage of the amplifier will be $.....V$.

The symbol given below represents: