Key Concept According to Brewster law, when a beam of unpolarized light is reflected from a transparent medium, the reflected light is completely plane polarized at a certain of incidence, called angle of polarization. Given, Brewster's angle, θ=60∘ We know that, µ=tanθ.....(1) ⇒µ=tan60∘=√3 Now, µ=
sini
sinI
⇒sinr=
sini
µ
=
sin60∘
√3
⇒
√3/2
√3
⇒sinr=
1
2
⇒r=sin−1(
1
2
)=30∘
Angle of deviation inside the glass, d=i−r=60∘−30∘=30∘