$A$ transistor has $3$ impurity regions of different doping levels. In the order of increasing doping level,the regions are

In a common emitter amplifier,a change of $0.2 \text{ mA}$ in the base current causes a change of $5 \text{ mA}$ in the collector current. If the input resistance is $2 \text{ k}\Omega$ and the voltage gain is $75$,what is the load resistance used in the circuit?

An $n-p-n$ transistor can be considered to be equivalent to two diodes connected back-to-back. Which of the following figures correctly represents this equivalent circuit?

The value of $I_c$ for the configuration shown is in $mA$.

For a common emitter transistor,the current gain is $50$,the input resistance is $1 \ k\Omega$,and the input voltage is $0.01 \ V$. What is the collector current?

An unknown transistor needs to be identified as a $npn$ or $pnp$ type. $A$ multimeter,with $+ve$ and $-ve$ terminals,is used to measure resistance between different terminals of the transistor. If terminal $2$ is the base of the transistor,then which of the following is correct for a $pnp$ transistor?