A ray of lighyt is incident at an angle I on a glass slab of refractive index `mu`. The angle between reflected and refracted light is `90^@` Then the relationship between I and `mu` is

Options

A. I = `tan^(-1) ((1)/(n))`
B. tan i =n
C. i= n
D. cos i= n

Answer

B

Explanation

i+ r = `90^(@)`
Snell.s law
1 sin i= n sin r
`rArr sin i= n sin (90^(@) -i)`
`rArr " " tani = n`.