The speed of light in air is 3 x 10⁸ m/s. In medium X its speed is 2 x 10⁸ m/s and in medium Y the speed of light is 2.5 x 108 m/s. Calculate:

(a) airⁿx = ?

(b) airⁿy = ?

(c) aⁿy

Define Snell's law of refraction. A ray of light is incident on a glass slab at an angle of incidence of 60°. If the angle of refraction be 32.7°, calculate the refractive index of glass. (Given: sin 60° = 0.866 and sin 30° = 0.5).

The speed of light in vacuum and in two different glasses is given in the table below:

(a) Calculate the absolute refractive indexes of flint glass and crown glass.

(b) Calculate the relative refractive index for light going from crown glass to flint glass.

What is the speed of light in a medium of refractive index 1.4 if its speed in air is 3, 00,000 km/s?

The refractive index of glass is 1.7. Calculate the speed of light in glass. The speed of light in air is 3.0 x 10⁸ ms^-1