In an $n-p-n$ transistor,$10^{10}$ electrons enter the emitter in $10^{-6} \ s$. If $2\%$ of the electrons are lost in the base,the current amplification factor $\beta$ is:

$A$ transistor having $\alpha = 0.99$ is used in a common base amplifier. If the load resistance is $4.5 \, k\Omega$ and the dynamic resistance of the emitter junction is $50 \, \Omega$,the voltage gain of the amplifier will be:

When an $n-p-n$ junction transistor is used as an amplifier in common emitter mode,

What is the basic constitutional unit in the electronic circuit?

Given below are two statements:
Statement $I :$ $PN$ junction diodes can be used to function as a transistor,simply by connecting two diodes back-to-back,which acts as the base terminal.
Statement $II :$ In the study of transistors,the amplification factor $\beta$ indicates the ratio of the collector current to the base current.
In the light of the above statements,choose the correct answer from the options given below:

$A$ 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: