Reverse bias applied to a junction diode

The region near the junction of an unbiased $p-n$ junction diode is known as the depletion layer. This layer is depleted of

All the diodes are ideal. The current flowing in the $2\,\Omega$ resistor connected between the diodes $D_1$ and $D_2$ is: (in $,A$)

Find the current through the $1\,\Omega$ resistance in the given circuit.

In a $p-n$ junction diode, an electric field of magnitude $2 \times 10^5 \ V/m$ exists in the depletion region. $A$ particle with charge $-3e$ can diffuse from $n$-side to $p$-side, if it has a minimum kinetic energy of $0.6 \ eV$. The width of the depletion region of the $p-n$ junction is: (in $nm$)

When and why is a $p-n$ junction called forward biased? Describe the changes that occur under such bias.