# What are the spherical mirrors? & Some concepts related to spherical mirrors

The spherical mirror is a mirror which has the shape of a piece cut out of a spherical surface, There are two types of spherical mirrors which are the concave mirrors (The converting mirrors) and the convex mirrors (the diverging mirrors).

## Spherical mirrors

The spherical mirror is a mirror that its reflecting surface is a part of a hollow sphere, The stainless-steel spoon is considered as a spherical mirror as its inner surface is a concave mirror while its outer surface is a convex mirror.

The shaving mirrors and the makeup mirrors are the most commonly occurring examples of concave mirrors and they magnify the objects placed close to them.

The most commonly occurring examples of convex mirrors are the passenger-side wing mirrors of cars, and they have wider fields of view than the equivalent flat mirrors but the objects that appear in them generally look smaller and, therefore, farther away than they actually are.

The concave mirror (The converting mirror) is a mirror that its reflecting (or shining) surface is a part of the inner surface of the sphere, It converges (collects) the light rays after the reflection.

The convex mirror (the diverging mirror) is a mirror that its reflecting ( or shining ) surface is a part of the outer surface of the sphere, It diverges the light rays after the reflection.

#### Some concepts related to the spherical mirror

The mirror center curvature is the sphere center in which the mirror is considered a part of it, It lies in front of the reflecting surface in the concave mirror and it lies behind the reflecting surface in the convex mirror.

The radius of mirror curvature is the radius of the sphere that the mirror is a part of it, It is the distance between the center of mirror curvature and any point on its surface.

The mirror pole is the point which is in the middle of the reflective surface of the mirror, The principal axis of the mirror is known as the straight line that passes by the pole of the mirror and its center of curvature.

The secondary axis of the mirror is any straight line that passes by the curvature center of the mirror and any point on its surface except the mirror pole.

The focus of the mirror (the principal focus) is the point of collection of the reflected light rays (in the concave mirror) or their extensions (in the convex mirror).

The focus of the mirror is produced when a parallel beam of rays is incident parallel to the principal axis of a spherical mirror, It is real in the case of the concave mirror and it is virtual in case of the convex mirror.

The focal length of the mirror is the distance between the mirror focus and the mirror pole, Each spherical mirror has an uncountable number of secondary axes and only one principal axis.

Uses of the concave mirror and the convex mirror in our daily life

The properties of the image formed by a plane mirror

The types and uses of lenses in our life

The uses of lenses to treat the vision defects