To use a transistor as an amplifier,which of the following conditions must be satisfied?

In an $NPN$ transistor circuit,the collector current is $10 \,mA$. If $90\%$ of the electrons emitted reach the collector,the emitter current $(i_E)$ and base current $(i_B)$ are given by

In the case of $NPN$ transistors,the collector current is always less than the emitter current because:

$A$ transistor is used in common-emitter mode in an amplifier circuit. When a signal of $10 \, mV$ is added to the base-emitter voltage, the base current changes by $10 \, \mu A$ and the collector current changes by $1.5 \, mA$. The load resistance is $5 \, k\Omega$. The voltage gain of the transistor will be

In the given common emitter transistor circuit,the base current is $I_B = 40 \, \mu A$. Determine the base-emitter voltage $V_{BE}$. (in $, V$)

In a common emitter $(CE)$ amplifier having a voltage gain $G,$ the transistor used has transconductance $0.03\, mho$ and current gain $25.$ If the above transistor is replaced with another one with transconductance $0.02\, mho$ and current gain $20,$ the voltage gain will be