The base current in a transistor circuit changes from $45 \mu A$ to $140 \mu A$. Accordingly, the collector current changes from $0.2 \text{ mA}$ to $4.0 \text{ mA}$. The gain in current is

The part of a transistor which is heavily doped to produce a large number of majority carriers is

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

$A$ common emitter amplifier has a voltage gain of $50$,an input impedance of $100\; \Omega$,and an output impedance of $200\; \Omega$. The power gain of the amplifier is:

An $n-p-n$ transistor is biased to work as an amplifier. Which of the following statements is $NOT$ correct?

In the study of a transistor as an amplifier,if $\alpha = \frac{I_C}{I_E} = 0.98$ and $\beta = \frac{I_C}{I_B} = 49$,where $I_C, I_B,$ and $I_E$ are collector,base,and emitter currents respectively,then $\left(\frac{1}{\alpha} - \frac{1}{\beta}\right)$ is equal to: