Question

For a prism of refractive index 1.732, the angle of minimum deviation is equal to the angle of the prism. The angle of the prism is [CBSE PMT 2001]
A) 80o B) 70o C) 60o D) 50o

Answer 1

the answer is 60degrees

Answer 2

Hey !!

Option (C) 60°

STEP BY STEP EXPLANATION

Μ = sin (A + δm / 2) / sin (A/2)

1.732 = √3

Given,

         A = δm

= √3 = sin (A + A / 2) / sin A/2

= √3 = sin 2 A/2 / sin A/2               [ ∴ cancel denominator 2 ]

= √3 = 2 sin A/2 . cos A/2 / sin A/2

= √3/2 = cos A/2

  A/2 = 30

=> A = 60°

GOOD LUCK !!