A ray of light is incident on the hypotenuse of a right angled prism after travelling parallel to the base inside the prism. If `mu` is the refractive index of the material of the prism, the maximum value of the base angle for which light is totally reflected from the hypotenuse is

Options

A. `sin^(-1)(1/mu)`
B. `tan^(-1)(1/mu)`
C. `sin^(-1)((mu-1)/mu)`
D. `cos^(-1)(1/mu)`

Answer

D

Explanation

An angle made by the light incident on the hypotenuse of a right angled prism is given by,
`implies mu=1/(sinC)`
`=1/(sin(90^@-theta)) = 1/(costheta)`
`implies costheta= 1/mu`
`theta=cos^(-1)(1/mu)`