What are the spherical mirrors ?
The spherical mirror
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 ) .
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 .
Some concepts related to the spherical mirror
The mirror center curvature is the sphere center 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 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 uncountable number of secondary axes , and only one principal axis .