Unpolarised light is incident from air on a plane surface of a material of refractive index `mu`. 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?

Options

A. `i=sin^(-1)(1/mu)`
B. Reflected light is polarised with its electric vector perpendicular to the plane of incidence.
C. Reflected light is polarised with its electric vector parallel to the plane of incidence.
D. `i=tan^(-1)(1/mu)`

Answer

B

Explanation

The figure shown below represents the course of path an unpolarised light follows when it is incident from air on plane surface of material of refractive index `mu.`

when the beam of unpolarised light is reflected from a medium (refractive index = `mu` and if reflected and refracted light are perpendicular to each other. Then, the reflected light is completely plane polarised at a certain angle of incidence. This means, the reflected light has electric vector perpendicular to incidence plane.