In a transistor circuit, if emitter and collector connections are interchanged, then:

If $\alpha$ is the current gain in a $CB$ circuit and $\beta$ is the current gain in a $CE$ circuit,then $\alpha / \beta$ = ......

The transistors provide good power amplification when they are used in

Given below are two statements: One is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: $n-p-n$ transistor permits more current than a $p-n-p$ transistor.
Reason $R$: Electrons have greater mobility as a charge carrier.
Choose the correct answer from the options given below:

For $I_b = 20 \ \mu A$ and $\beta = 100$,the value of the emitter current is ........ $mA$.

In a common emitter configuration, a transistor has $\beta=50$ and input resistance $1 \text{ k}\Omega$. If the peak value of a.c. input is $0.01 \text{ V}$, then the peak value of collector current is: (in $\mu\text{A}$)