Question

A reflected light becomes completely polarised when corresponding incident angle is ${60}^o$. When light is incident on the substance. Determine the velocity of refracted ray in the medium.

Answer 1

The incidence angle at which an incident light becomes completely polarised is called Brewster's angle which is given by relation,

$\frac{{\mu }_2}{{\mu }_1}=tan{\theta }_B$
$⟹\mu =tan{60}^{\circ }$

$=\sqrt{3}$

Hence the velocity of refracted ray in the medium=$\frac{c}{\mu }$

$=\sqrt{3}\times {10}^{8}m/s$