Question

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

• A. $i={\tan }^{-1}(\frac{1}{\mu })$
• B. Reflected light is polarised with its electric vector parallel to the plane of incidence
• C. $i={\sin }^{-1}(\frac{1}{\mu })$
• D. Reflected light is polarised with its electric vector perpendicular to the plane of incidence

Answer 1

Answer: (D)

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

Also, $\tan i=\mu$ (Brewster angle)