Question

Light travels from material #1 with refractive index n₁ and incidence angle θ₁ into material #2 with refractive index n₂ and refraction angle θ₂. Choose the correct statement below.
If θ₁ < θ₂, then material #1 has a smaller index of refraction.
If θ₁ > θ₂, then material #1 has a larger index of refraction.
If θ₁ > θ₂, then material #1 has a smaller index of refraction.
If θ₁ < θ₂, then light travels slower in material #2.
If θ₁ < θ₂, then material #2 has a larger index of refraction.

Answer 1

By Snell’s law,

n₁sinθ₁ = n₂sinθ₂

n₂ = n₁*(sinθ₁/sinθ₂)

If, θ₁ > θ₂ => sinθ₁/sinθ₂ > 1

Gives, n₂ > n₁

It means, material #1 has smaller index of refraction.

If, θ₁ < θ₂ => sinθ₁/sinθ₂ < 1

Gives, n₂ < n₁

It means, material #1 has larger index of refraction.