Question

Greenlight is an incident at the polarising angle on a certain transparent medium. The angle of refraction is 30°.
Find
(i) polarising angle, and
(ii) refractive index of the medium.

Answer 1

(i) when the light is incident at the polarizing angle, the angle of refraction and angle of polarization are related according to the equation,

∠i_p + ∠r = 90°

The angle of refraction is given as, 30°. So the angle of polarization, ∠i_p = 90° - 30° = 60°

(ii) Applying Snell's law, we can write, the refractive index of the transparent media,` mu = sin"i"_"p"/sin "r"`

⇒ `mu = sin60^@/sin30^@ = (sqrt3/2)/(1/2) = sqrt3`

⇒ ` = mu sqrt3`