A prism of refracting angle `60^(@)` is made with a material of refractive index `mu`. For a certain wavelength of light, the angle of minimum deviation is `30^(@)`. For this, wavelength the value of refractive index of the material is

Options

A. `1.820`
B. 1.503
C. 1.414
D. 1.231

Answer

C

Explanation

`A = 60^(@), delta_(m) = 30^(@), mu = ?`
`mu = (sin((A+delta_(m))/(2)))/(sin((A)/(2))) = (sin((60+30)/(2)))/(sin((60)/(2)))`
`= (sin 45)/(sin 30) = sqrt(2) = 1.414`