TECHNICAL TERMS ASSOCIATED WITH SPHERICAL MIRRORS
Centre of curvature (c)
Centre of sphere of which the mirror is assumed to be a part, is called as centre of curvature of the mirror. Denoted by the letter c. And line drawn from centre of curvature to mirror is normal to the mirror.
Radius of curvature (R)
Radius of the sphere in which mirror is a part, is called as radius of curvature. Denoted as R. In the picture CB, CP, and CA are radius of curvature.
Aperture of the mirror
Aperture of mirror is the reflecting surface of the mirror
Pole of the mirror (P)
Pole of the mirror is the midpoint of the reflecting surface of the mirror. Denoted as P.
Principal axis
Principal axis of a mirror is the straight line connecting the pole of a mirror and the centre of curvature of the mirror