In the given mirror
C – centre of the sphere to which the mirror is part of
F – focus of the mirror
P – pole of the mirror
A – point on the mirror
D – point on the principal axis.
If a ray of light starts from C and is incident on A from which point will the reflected ray pass through?
C
CA will fall normally to the concave mirror and the angle of incidence is 0∘. By laws of reflection, we know that the angle of reflection will be 0∘. Hence the ray will retrace its path and pass through C (centre of curvature).