Question

Define (a) centre of curvature (b) radius of curvature (c) pole (d) principal axis, and (e) aperture, of a spherical mirror with the help of a labelled diagram

Answer 1

(a) Centre of curvature (C) – It is the centre of the sphere from which the mirror is formed.
(b) Radius of curvature (R) – It is the radius of the sphere from which the mirror is formed.
                                              R = PC
                                          

(c) Pole (P) – Pole is the centre of the curved mirror surface, MM’.
(d) Principal axis – It is the line joining P and C.
(e) Aperture – It is the effective length of the mirror, i.e. MM’.