A ray of light travelling in the direction `1/2 (hati+sqrt(3)hatj)` is incident on a plane mirror. After reflectiion, it travels along the direction `1/2(hati+sqrt(3)hatj)`. The angle of incidence is

Options

A. `30^(@)`
B. `45^(@)`
C. `60^(@)`
D. `75^(@)`

Answer

A

Explanation

Component along the plane
`=1/2` and component
Perpendicular to the plane `=(sqrt(3))/2`
`:.tan i =((1/2))/(((sqrt(3))/2))=1/(sqrt(3))`
`i=30^(@)=` angle of incidence