White light is incident on one of the refracting surface of a prism of angle `5^(@)`. If the refractive indices for red and blue colours are 1.641 and 1.659 respectively, the angular separation between these two colours when they emerge out of the prism is

Options

A. `0.9^(@)`
B. `0.09^(@)`
C. `1.8^(@)`
D. `1.2^(@)`

Answer

C

Explanation

Angular dispersion, `delta_(b)-delta_(r )=(mu_(b)-mu_(r ))A`
`delta_(b)-delta_(r )=(1.659-1.641)5^(@)=0.09^(@)`