Question

(a) A ray of light, after refraction through a concave lens, emerges parallel to the principal axis. Draw a ray diagram to show the incident ray and its corresponding emergent ray. 

(b) The velocity of light in diamond is 21,000kms^-1 What is its refractive index of diamond? (Velocity of light in a air 3 × 10⁸m/s)

Answer 1

Refractive index = (3 x 10⁸)/1.21 x 10⁸) = 3/1.21 = 2.47