For a prism kept in air, it is found that for an angle of incidence `60^(@)`, the angle of refraction A, angle of deviation `delta` and anble of emergence e become equal. Then, the refractive index of the prism is

Options

A. 1.73
B. 1.15
C. 1.5
D. 1.33

Answer

a.

Explanation

Given `i=60^(@)` and `A=delta=e`
`delta=i+e-ArArrdelta=1( :.e=A)`
`mu=("sin"((A+delta_(m))/2))/("sin" A/2)`
Here, angle of deviation is minimum ` ( :'i=e)`
`mu=("sin"((60^(@)+60^(@))/2))/(sin(60^(@)//2))=1.73`