Question

A Prism has reflecting angle of 60° when a ray is incident at 50° it suffer minimum deviation (Sm). The value of Sm is

Options

• 45°

• 60°

• 55°

• 40°

Answer 1

40°

Explanation:

In the position of least deviation

i₁ = 1₂ = 50°, A = 60°

From A + Sm = i₁ + i₂

Sm = i₁ + i₂ – A = 50 + 50 – 60 = 40°