Question

A ray of light passes through a transparent media with refractive index n₁, n₂, n₃, n₄ as shown in the figure. The surface of all the medias are parallel. If the emergent ray CD is parallel to the incident ray AB, we must have 

1) n₁ = n₂ 

2) n₂ = n₃ 

3) n₃ = n₄ 

4) n₄ = n₁

Answer 1

Correct option is 4) n₄ = n₁

Multiplying these equations,

\(\cfrac{n_4}{n_1} = 1\)