A ray of light is incident on a transparent glass slab of refractive index `sqrt3`. If the reflected and refracted rays are mutually perpendicular, what is the angle of incidence?

Explanation

From the figure, `i+90^(@)+r=180^(@)`
or, `i+r=90^(@)orr=90^(@)-i`
`thereforemu=sini/sinr=sini/(sin(90^(@)-i))=sini/cosi=tani`
`thereforei=tan^(-1)(mu)=tan^(-1)(sqrt3)=60^(@)`