Question

A certain material has refractive indices 1.56, 1.60 and 1.68 for red, yellow and violet light respectively. (a) Calculate the dispersive power. (b) Find the angular dispersion produced by a thin prism of angle 6° made of this material.

Answer 1

Correct Answer - A::B
Given that `mu_r=1.56,`
`mu_y=1.60, and mu_c=1.68` a. Dispersive power `=omega`
`=(mu_v-mu_r)/(mu_y-1)=(1.68-1.56)/(1.60-1)`
`=0.12/0.60=0.2`
b. Angular dispersion `=(mu_r-mu_r)a`
`=(0.12)xx6^@=0.72^@`