Question

The reflected light is found to be plane polarised when an unpolarized light falls on a denser medium at 60° with the normal. Find the angle of refraction and critical angle of incidence for total internal reflection in the denser to rarer medium reflection.

Answer 1

60° + r + 90° = 180°

60° + r = 90°

r = 30°

Angle of refraction = 30°

c = ?

`mu = 1/(sin "c")`

`mu = (sin "i")/(sin "r")`

`mu = (sin 60)/(sin 30)`

= `(sqrt3/2)/(1/2)`

`= sqrt3`

`mu = 1/(sin "c")`

sin c = `1/mu`

sin c = `1/sqrt3`

c = `sin^-1 (1/sqrt3)`

c = 35.15°