For a transistor amplifier in a common-emitter configuration,given the load resistance $R_L = 1 \ k\Omega$,$h_{fe} = 50$,and $h_{oe} = 25 \ \mu A/V$,calculate the current gain $(A_i)$.

In an $NPN$ transistor,the collector current is $20 \, mA$. If $90\%$ of the electrons emitted reach the collector,then:

Consider the circuit arrangement shown in figure $(1)$ for studying input and output characteristics of an $n-p-n$ transistor in $CE$ configuration. Select the values of $R_B$ and $R_C$ for a transistor whose $V_{BE} = 0.7 \, V$, so that the transistor is operating at point $Q$ as shown in the characteristics shown in figure $(2)$. Given that the input impedance of the transistor is very small and $V_{CC} = V_{BB} = 16 \, V$, also find the voltage gain and power gain of the circuit making appropriate assumptions.

$A$ common emitter circuit is used as an amplifier with a current gain of $50$. If the input resistance is $1 \ k\Omega$ and the input voltage is $5 \ V$, then the output current is ....... $mA$.

In an $n-p-n$ transistor,$200$ electrons enter the emitter in $10^{-8} \ s$. If $1 \%$ of electrons are lost in the base,then the current that enters the emitter and the current amplification factor are respectively $\left[e=1.6 \times 10^{-19} \ C\right]$

The output characteristics of a transistor are shown in the figure. When $V_{CE} = 10\, V$ and $I_{C} = 4.0\, mA$,then the value of $\beta_{ac}$ is: