Question

What is meant by the statement, ‘the critical angle for diamond is 24°’? How is the critical angle of a material related to its refractive index?

Answer 1

(i) It means that when a light ray is incident inside a diamond at an angle greater than 24°, the light will be totally internally refracted. 

(ii) Relation of critical angle and refractive index:

 Where μ = refractive index of material and C = critical angle.