Question

Refractive index of material of a prism is `sqrt(2)`. The angle of prism is 60°, What is the angle of minimum deviations?

Options

• 60°

• 75°

• 30°

• 90°

Answer 1

30°

Explanation:

`mu = (sin(A + Sm)/2)/(sin  A/2)`

`(sin(A + Sm))/2 = mu sin  A/2 = sqrt(2) sin  60^circ/2 = sqrt(2)/2`

= `1/sqrt(2) (A + Sm)/2` = 45°, Sm = 90° – A = 90° – 60°

= 30°