When light is polarised by reflection from a transparent surface.
a) reflected and refracted rays are mutually perpendicular
b) both reflected and refracted rays are plane polarised
c) refracted ray is partially polarised
d) the R.I., of transparent surface is equal to tangent of Brewster’s angle

When light falls on an interface between two transparent media at a particular angle called the polarization angle or the Brewster angle, the light will completely pass through into the second medium without any reflection if the light incident is linearly polarized. If the light incident is unpolarized, then the reflected will be completely polarized. This only happens when the refracted and the reflected rays are mutually perpendicular, and always ${\mathrm{Tani}}_{\mathrm{p}}=\frac{{\mathrm{\mu }}_2}{{\mathrm{\mu }}_1}$.