Question

An unpolarised light beam travelling in air is incident on a medium of refractive index 1.73 at Brewster’s angle. Then, ______.

विकल्प

• reflected lights is completely polarised and the angle of reflection is close to 60°.

• reflected light is partially polarised and the angle of reflection is close to 30°.

• both reflected and transmitted lights are perfectly polarised with angles of reflection and refraction closer to 60° and 30°, respectively.

• transmitted light is completely polarised with angle of refraction close to 30°.

Answer 1

An unpolarised light beam travelling in air is incident on a medium of refractive index 1.73 at Brewster’s angle. Then, reflected light is completely polarised and the angle of reflection is close to 60°.

Explanation:

When unpolarised light is incident at polarising (Baewster's) angle, the reflected light is completely polarised and the transmitted light is partially polarised.

From theory

`tan i_p = sqrt3 = 1.73`

i_p = 60

According to the law of reflection,

r = i_p

= 60°