Draw a labelled diagram of full wave rectifier using p-n junction diodes.

A doped semiconductor has  impurity levels $0.01 \mathrm{eV}$ above the valence band. Is it an n-type semiconductor or p-type?

The band gap between the valence and the conduction bands in Germanium is $0.7 \mathrm{eV}$. If an electron in the conduction band combines with a hole in the valence band and the excess energy is released in the form of electromagnetic radiation. Find the maximum wavelength that can be emitted in the process.

In a p-n junction, the depletion region is $2 \mathrm{\mu m}$ wide and an electric field of $1.0 \mathrm{x} {10}^5 \mathrm{v} {\mathrm{m}}^{-1}$ exists in it. Find the height of the potential barrier.

In a p-n junction, the depletion region is $2 \mathrm{\mu m}$ wide and an electric field of $1.0 \mathrm{x} {10}^5 \mathrm{v} {\mathrm{m}}^{-1}$ exists in it. What should be the minimum kinetic energy of a conduction electron which can diffuse from n-side to p-side ?

The potential barrier of $0.25 \mathrm{V}$ exists across an unbiased p-n junction. What minimum kinetic energy a hole should have to diffuse from p-side to n-side if the junction is unbiased.