Question

A ray of light in air is incident on a glass plate at 45°. The refractive index of glass is 1.5. What is the angle of refraction?

Answer 1

Given: Refractive index of air, n₁ = 1

Angle of incidence, i = 45°

Refractive index of glass, n₂ = 1.5

To find the angle of refraction, we use Snell’s law:

n₁ sin i = n₂ ​sin r

1 × sin 45° = 1.5 × sin r

0.7071 = 1.5 × sin r

sin r = `0.7071/1.5`

sin r ≈ 0.4714

r = sin⁻¹ (0.4714)

r ≈ 28°