A ray of light travelling in a transparent medium f refractive index `mu`, falls on a surface separating the medium from air at an angle of incidence of `45^(@)`. For which of the following value of `mu` the ray can undergo total internal reflection ?

Options

A. `mu=1.33`
B. `mu=1.40`
C. `mu=1.50`
D. `mu=1.25`

Answer

C

Explanation

For total internal reflection, sini `gt` sinC where,
i = angle of incidence
C = critical angle
But, `sin C =(1)/(mu) :. Sinigt(1)/(mu) "or" mu gt (1)/(sini)`
`mugt(1)/(sin45^(@))(i=45^(@) (Given))`
`mugtsqrt(2)`
Hence, option (c ) is correct.