Question

By how much do the critical angles for orange (610 nm) and blue (470 nm) light differ in polystyrene surrounded by air?

Answer 1

Solution:

Refractive index of polystyrene = 1.589 (for orange) = n1

Refractive index of polystyrene for blue = 1.609 =n2

Critical angle = C

sin C = 1 / n1 for orange

C1 = sin^-1 (1/1.589) = 39 degrees for orange light

C 2= sin^-1(1/1.609) = 38.426 for blue light

Difference in the critical angles = C1-C2 = 39 - 38.426

                                                               = 0.574 degrees