The critical angle for light going from medium X into medium Y is `theta` . The speed of light in medium X is v. The speed of light in medium Y is

Options

A. `v_(A) tan theta `
B. `(v_(A))/(tan theta)`
C. `(v_(A))/(sin theta)`
D. `v_(A) sin theta`

Answer

C

Explanation

The ray is going from medium A to medium B . Since there is a critical angle `(theta)` , the medium A is an optically denser medium and the medium B is optically rarer . For this sin `theta = (n_(B))/(n_(A))`
But `(n_(B))/(n_(A)) = (C)/(v_(B)) xx (v_(A))/(v_(C)) = (v_(A))/(v_(B))`
`therefore sin theta = (v_(A))/(v_(B)) therefore v_(B) = (v_(A))/(sin theta)`