Question

State Brewster's law.
The values of Brewster angle for a transparent medium is different for light rays of different colours. Give good reasons why.

Answer 1

Brewster's Law: It states that when light is incident at polarising angle at the interface of a refracting medium, the refractive index of the medium is equal to the tangent of the polarising angle.
As Brewster angle depends on the refractive index and wavelength, so it is different for different colours
when a light is incident on transparent polarsing angle the reflected nd refracted are perpendicular to each other.as lights of different color ss have different wavelength , hence have different values of refractive index of medium. that is why. these light have values of different brewsters angles....
hope it help

Answer 2

Good Morning Sir,

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) is given by

              μ = tan ip , where ip = polarising angle.

Since refractive index is different colour ( wavelengths ), Brewster's angle is different for different colours.

:-)