Question

What is Brewster’s angle? Derive relation between Brewster angle and refractive index of medium which produces Plane Polarized light. 

Answer 1

“The angle of incidence at which the reflected light is completely plane polarized, is called as Brewster’s angle (i_B) 

At i = i_B, reflected beam 1 to refracted beam 

∴ i_B + r = 90 ⟹ r = 90 - i_B

Using snell’s law

(sin i)/ (sin r) = μ

(sin i_B)/sin(90 - i_B) = μ

(sin i_B)/ (cos i_B) = μ

μ = tan i_B