A ray of light falls on a transparent sphere with centre at C as shown in figure. The ray emerges from the sphere parallel to line AB. The refractive index of the sphere is

Answer

`sqrt(3)`

Explanation

From snell's law
`1 . "sin"60^(@) = mu"sin"r` (at Pt'Q')
`therefore` sin 2r = sin `60^(@)`
r = `30^(@)`
`therefore 1. "sin"60^(@) = mu "sin"30^(@) implies mu = sqrt(3)`