(a) Describe briefly, with the help of suitable diagram, how the transverse nature of light can be demonstrated by the phenomenon of polarization.
(b) When unpolarized light passes from air to a transparent medium, under what condition does the reflected light get polarized?

Explanation

(a) Polarization : The dots and arrow indicates that both polarization are present in the incident and refracted waves.
Only transverse wave can be polarized. And the transverse nature of light can be demonstrated by the polarization. Light can be polarized by reflecting it from a transparent medium. The extend of polarization by reflecting it from a transparent medium. The extend of polarization depend on the angle of incient, at a particular angle of incidence, called Brewster

(b) Unpolarized light : The independent light waves whose planes of vibrations are randomly oriented about the direction of propagation are said to be unpolarized light.
When unpolarized light is incident on the boundary between two transparent media, the reflected light i polarized with electric vector perpendicular to the plane of incidence when the refracted and reflected rays make a right angle with each other.