Question

State and proof brewster law with diagram ? Need detail answer

Answer 1

Brewster law states that-

When unpolarised light of suitable wavelength is incidence upon transparent substance it experiences maximum polarisation at the angle of incidence for which the angle between reflected ray and refracted ray is 90 degrees is called as angle of polarisation

Or

Tan of angle of polarisation is equal to refractive index of the medium

Proof-

Using snells law -

u(air)*Sin i = u(medium)*Sin r

1*Sin i = u(medium)*Sin r

Now r = 90-i as shown in figure

Sin i / Sin(90-i) = u(medium)

Sin i / cos i = u(medium)

tan i = u(medium)

Hence proved :)