A unit vector along the incident ray of light is `hat(i)`. The unit vector for the corresponding refracted ray of light is `hat(r ).hat(n)`, a unit vector normal to the boundary of the medium and directed towards the incident medium. If `mu` is the refractive index of the medium, then snell's law (second law) of refraction is

Options

A. `hat(i)xxhat(n)=mu(hat(n)+vec(r))`
B. `hat(i).hat(n)=mu(hat(r ).hat(n))`
C. `hat(i)xxhat(n)=mu(hat(r )xxhat(n))`
D. `hat(i)xxhat(n)=mu(hat(r )xxhat(n))`

Answer

C

Explanation

You have to try all the options. Let us discuss the correct option only.

`hat(i)xxhat(n)=mu(hat(r )xxhat(n))`
`(1)(1)sin (180^(@)-hat(i))= mu(1)(1)(180^(@)-r)`
`sini=mu sin r`