Distinguish between ‘intrinsic’ and ‘extrinsic’ semiconductors.

A proton and an -particle have the same de-Broglie wavelength. Determine the ratio of

(i) Their accelerating potentials

(ii) Their speeds.

Show that the radius of the orbit in hydrogen atom varies as n2, where n is the principal quantum number of the atom.

Use the mirror equation to show that an object placed between f and 2f of a concave mirror produces a real image beyond 2f.

Find an expression for intensity of transmitted light when a Polaroid sheet is rotated between two crossed Polaroid. In which position of the Polaroid sheet will the transmitted intensity be maximum?