Define barrier potential for reverse biased p-n junction with diagram

The $V-I$ characteristic of a diode is shown in the figure. The ratio of forward to reverse bias resistance is:

Identify the semiconductor devices whose characteristics are given below, in the order $\left(\mathrm{a}\right),\mathrm{ }\left(\mathrm{b}\right),\mathrm{ }\left(\mathrm{c}\right),\mathrm{ }\left(\mathrm{d}\right)$:

If the Ge diode in the circuit is reverse biased, the current through $2\mathrm{k\Omega }$ resistor

The non-zero potential difference across diode $D_1$ and that across diode $D_2$ are equal in the circuit shown in the figure (both the diodes are identical in characteristics)

In the following circuit, the equivalent resistance between $A$ and $B$ is

Determine the current passing through the diode $D_2$ in the circuit given. Assume these are Silicon diodes.

A $5 \mathrm{V}$ battery is connected across the points $X$ and $Y$. Assume $D_1$ and $D_2$ to be normal silicon diodes. Find the current supplied by the battery if the $+ve$ terminal of the battery is connected to point $X$.

The given circuit has two ideal diodes connected as shown in the figure below. The current flowing through the resistance $R_1$ will be