In the given mirror
C – The center of the sphere to which the mirror is part of
F – The focus of the mirror
P – Pole of mirror
A – Point on the mirror
D – The 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 so by laws of reflection the angle of incidence is 0∘ and so the angle of reflection will be 0∘. Hence the ray will retrace its path and pass through C (center of curvature).