What is the angle of incidence for an equilateral prism of refractive index `sqrt(3)` so that the ray si parallel to the base inside the prism?

Options

A. `30^(@)`
B. `45^(@)`
C. `60^(@)`
D. either `30^(@)` or `60^(@)`

Answer

C

Explanation

`sqrt(3)=(sin((60^(@)+delta_(m))/(2)))/(sin((60^(@))/(2)))`
`sqrt(3)=sin ((60^(@)+delta_(m))/(2))`
`sin60^(@)=sin((60^(@)+delta_(m))/(2))`or `(60^(@)+delta_(m))/(2)=60^(@)`
or `d_(m)=60,i=(A+delta_(m))/(2)=(60^(@)+60^(@))/(2)=60`