State Brewster's Law
The value of Brewster angle for a transparent medium is different for light of different colours .
Give reason.

Explanation

Brewster’s Law: When unpolarised light is incident on the surface separating two media at polarising angle, the reflected light gets completely polarised only when the reflected light and the refracted light are perpendicular to each other.
Now, refractive index of denser (second) medium with respect to rarer (first) medium is given by
`mu=tani_p` where `i_p` = polarising angle.
Since refractive index is different for different colour (wavelengths), Brewter’s angle is different for different colours.