In the following cases, a ray is incident on a concave mirror. In which case is the angle of inciden

Question

In the following cases, a ray is incident on a concave mirror. In which case is the angle of incidence equal to zero?\

Professor PC Thomas Classes · Answer

(b): When a ray of light passes through the centre of curvature of a concave mirror it strikes the mirror along the normal i.e., it incidences on to the mirror at an angle of $90^{\circ}$ and makes $0^{\circ}$ with normal. Hence, the incident ray coincides with the normal. Therefore, angle of incidence is zero degree for the case when a ray passing through the centre of curvature and incident obliquely.