A ray of light is incident normally on a plane mirror. What will be the:(a) angle of incidence?(b) angle of reflection?

(a) The angle of incidence is 0° because the incident ray is parallel to the normal.

(b) The angle of reflection is 0° according to the law of reflection, which states that the angle of incidence is equal to the angle of reflection.

Explanation

 When light is thrown at an angle of 90° or along the normal to the mirror then the angle of reflection and angle of incidence will be the same and they will be equal to zero degrees (0°). Hence, the light after striking the mirror retraces or return to its own path.