If a transistor having $\alpha = 0.9$ is used in $CE$ configuration, then for a change of $0.4 \text{ mA}$ in base current, what will be the change in collector current (in $\text{ mA}$)?

The base current is $100 \mu A$ and the collector current is $3 \text{ mA}$. $A$ change of $20 \mu A$ in the base current results in a change of $0.5 \text{ mA}$ in the collector current. The value of $\beta_{ac}$ is:

In a common emitter transistor amplifier,the audio signal voltage across the collector is $3\,V$. The resistance of the collector is $3\,k\Omega$. If the current gain is $100$ and the base resistance is $2\,k\Omega$,what are the voltage and power gain of the amplifier?

For a transistor,current gain $(\beta) = 50$. To change the collector current by $350 \mu A$,the base current should be changed by:

In $n-p-n$ transistor, in $CE$ configuration:

In common emitter configuration of a transistor amplifier, $r_i$, $R_L$ and $\beta$ represent the input resistance, load resistance, and the a.c. current gain, respectively. The voltage gain $A_V$ and power gain $A_P$ are represented in magnitude by which of the following expressions?