What is a common base amplifier?

The typical output characteristics curve for a transistor working in the common-emitter configuration is shown in the figure.

The estimated current gain from the figure is

In the circuit shown, the value of $\beta$ of the transistor is $48$. If the supplied base current is $200 \mathrm{\mu A}$, what is the voltage at the terminal $Y$?

Correct the following sentence: The relation between transistor constants $\beta$ and $\gamma$ is $\gamma =1-\beta$.

Represent the union of two sets by Venn diagram for each of the following.

$X=\{x | x$ is a prime number between $80$ and $100\}$

$Y=\{y | y$ is an odd number between $90$ and $100\}$