$A$ transistor has $3$ impurity regions of different doping levels. In the order of increasing doping level,the regions are

Three amplifiers,each having a voltage gain of $10$,are connected in series. The resultant gain would be

$A$ transistor works as an amplifier when

In a $CE$ amplifier,the input $ac$ signal to be amplified is applied across

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:

For a transistor,$\beta = 100$. The value of $\alpha$ is