SIGN CONVENTION FOR MIRRORS

A mirror is any surface that reflects the light rays falling on it. The sign convention for a mirror is a set of rules to set the signs of focal length, image distance, object distance, etc. Consider a mirror where P is the pole of the mirror, C is the center of curvature and F is the focal point,

The Pole of a mirror is the geometrical center of the spherical surface of a mirror. The Center of curvature is the center of the sphere of which the mirror surface is a part. The focal point is the point at which the rays passing parallel to the principal axis converge or appear to diverge after reflection.

Spherical mirrors are mainly of two types: Concave mirrors and Convex mirrors.

Concave mirrors, also known as converging mirrors are mirrors having a reflective surface that is curved inwards. These mirrors converge the light falling on them to the focal point.

IMAGE FORMATION BY CONCAVE MIRRORS

Convex mirrors, also known as diverging mirrors are mirrors having a reflective surface that is bulged outwards. These mirrors reflect the light falling on them and the light gets diverged after reflection.

IMAGE FORMATION BY CONVEX MIRRORS