Question

A ray is incident at 30 degree angle on plane mirror. What will be deviation after reflection from mirror

Answer 1

Hope you get what you want....

Answer 2

Answer:

The angle between the directions of the incident ray and the reflected ray can be defined as the deviation produced by a plane mirror (or, the emergent ray). It's usually represented by the symbol.

Explanation:

Let the angle Incidence be θ.

θ = $30$°

The incident ray will be reflected at a $30$° angle (made with a surface normal to the mirror surface). The deviation angle is equal to $2$* the glance angle. The incident angle is equal to the angle of reflection, according to the law. The perpendicular normal will be at a $90$° angle. We know that the incident angle equals the angle of reflection.

The reflected ray makes a angle with the mirror is 90°−θ:

If the incident ray had passed through the mirror without being reflected or refracted, the angle it would have made with the mirror would have been 90°−θ.

$90-30=60$

The angle between the incident ray's path and the reflected ray's path if the incident ray passed through the mirror without being reflected or refracted

The angle of deviation for a plane mirror are  $2$($90$°−θ)=$180$°−θ.

$2*(90-60)= 60$

$180- 60$°

=$120$°

As a result, delta =$120$°.