Question

1. The angle of minimum deviation for thin prism of refractive index () is
(1) (1-u)A
(2) (u-1) A
(3) (u+1) A
(4) (4+1)A2​

Answer 1

Answer:

For a thin prism, angle of minimum deviation is given by

δ=(μ−1)A

where,μ is refractive index of the prism and A the angle of prism.

For dispersion without deviation

δ1=δ2

⇒(μ1−1)A1=(μ2−1)A2

⇒A2=(μ1−1)(μ2−1)A1

Given, μ1=1.54,A1=4∘,μ2=1.72

⇒A2=(1.54−1)(1.72−1)×4=3∘

Explanation: