For a transistor,$\frac{1}{\alpha_{DC}} - \frac{1}{\beta_{DC}}$ is equal to [where $\alpha_{DC}$ and $\beta_{DC}$ are current amplification factors].

$A$ $CE$ amplifier has a voltage gain of $G$. The transistor used has a transconductance of $0.03 \ mho$ and a current gain of $25$. If this transistor is replaced by another transistor with a transconductance of $0.02 \ mho$ and a current gain of $20$,the new voltage gain will be ........

In a silicon transistor,a change of $7.89 \, mA$ in the emitter current produces a change of $7.8 \, mA$ in the collector current. What change in the base current is necessary to produce an equivalent change in the collector current (in $mA$)?

In the common emitter configuration of a transistor,the current gain is more than $1$. Given that $I_{b}$,$I_{e}$,and $I_{c}$ are the base,emitter,and collector currents respectively,which of the following relations is correct?

In common emitter mode of a transistor, the d.c. current gain is $20$, and the emitter current is $7 \,mA$. The collector current is (in $/ 3 \,mA$)

In a $PNP$ transistor,the base is the $N$-region. Its width relative to the $P$-region is