$A$ common emitter amplifier is designed with an $NPN$ transistor $(\alpha = 0.99)$. The input impedance is $1 \ k\Omega$ and the load resistance is $10 \ k\Omega$. The voltage gain will be:

For a transistor amplifier,the voltage gain:

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

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:

In a transistor $(\beta=50)$,the voltage across $5 \, k\Omega$ load resistance in the collector circuit is $5 \, V$. The base current is ......... $mA$.

For a transistor,the current amplification factor is $\alpha = 0.8$. The transistor is connected in a common emitter configuration. The change in the collector current when the base current changes by $6 \, mA$ is.....$mA$.