Question

Unpolarised light is incident from air on a plane
surface of a material of refractive index 'u'. At a
particular angle of incidence 'i', it is found that the
reflected and refracted rays are perpendicular to
each other. Which of the following options is
correct for this situation?

(1) Reflected light is polarised with its electric
vector parallel to the plane of incidence
(2) Reflected light is polarised with its electric
vector perpendicular to the plane of incidence
(3) i = tan^-1 (1/u)
(a) i= sin^-1(1/u)

u is meu​

Answer 1

Solution :

Correct option: (b) Reflected light is polarised with its electric vector perpendicular to the plane of incidence.

As we know that,

When reflected light and refracted light are perpendicular, reflected light is polarised with electric field vector perpendicular to the plane of incidence.

That is:

$\implies$ $\huge{\boxed{\sf{tan\:i = \mu}}}$ (Brewster angle)

Note:

Brewster angle: The special angle of incidence that produces a 90° angle between the reflected and refracted ray.

Answer 2

Answer:

Correct option: (b) Reflected light is polarised with its electric vector perpendicular to the plane of incidence.