When a ray of light is incident normally on one refracting surface of an equilateral prism (Refractive index of the material of the prism `=1.5`

Options

A. Emerging ray is deviated by `30`
B. Emerging ray is deviated by `45^(@)`
C. Emerging ray just grazes the second refracting surface
D. The ray undergoes total internal reflection at the second refracting surface

Answer

D

Explanation

Critical angle for the material of prism `C=sin^(-1)((1)/(mu))`
`=sin^(-1)=42^(@)` since angle of incidence at surface `AB(60^(@))` is greater then the critical angle `(42^(@))` so total internal reflection takes place.