Consider a configuration of n identical units, each consisting of three layers. The first layer is a column of air of height h = 1 3 cm , and the second and third layers are of equal thickness d = 3 - 1 2 cm , and refractive indices μ 1 = 3 2 and μ 2 = 3 , respectively. A light source O is placed on the top of the first unit, as shown in the figure. A ray of light from O is incident on the second layer of t

Step-by-step solution

Considering a single unit with three layers. The figure below shows the refraction of light as it moves from one medium to others. For the first interface, x 1 = 1 3 × tan 60 ° = 1 3   cm Using Snell's law, μ 1 sin θ 1 = μ 2 sin θ 2 ⇒ 1 × 3 2 = 3 2 × sin θ 2 ⇒ θ 2 = 45 ° For the second interface, ⇒ x 2 = d × tan 45 ° = d And again using Snell's law, 3 2 × sin 45 = 3 × sin θ 3 ⇒ 3 2 × 1 2 = 3 sin