When a forward bias is applied to a $p-n$ junction, it . . . . . . .

The $I-V$ characteristic of a $p-n$ junction diode is shown in the figure. Find the approximate dynamic resistance of the $p-n$ junction when a forward bias of $1 \text{ V}$ is applied. (in $\Omega$)

What is the current in the circuit shown below?

The cause of the potential barrier in a $p-n$ junction diode is

Currents flowing in each of the following circuits $A$ and $B$ respectively are

With forward bias mode,the $p-n$ junction diode