Image formed by convex mirror?

1 Answer
Mar 8, 2018


the image formed by convex mirrors are virtual , erect and smaller than the size of the object.


convex mirrors are such that its surface is spherical and protruded towards the observer.

the radius of the sphere R from which the convex mirrors are made is an important parameter , as half of the radius is the focal length of the convex mirror. so focal length of such mirrors are =R/2

The focal length or focus of the mirror can be found by pointing rays from a distant object and the bunch of parallel rays after reflection will appear to come from a point on the axis -this point is the focus of the mirror.

One can try to locate this virtual image with the help of another mirror say a plane mirror kept in front of the convex mirror.

The Image construction from a convex mirror will follow the same rule of reflection i.e.
The angle of incidence of incoming rays from the object measured from normal to the mirror at the point of incidence must be equal to the angle of reflection , the angle made by reflected ray to the normal.

The perpendicular at the surface will be line joining centre of the spherical mirror i.e. distant R the radius to the point under consideration..which is the point of incidence.

A ray diagram constructed on the above basis can help you a lot in understanding the behaviour of convex mirrors.

The property that it makes smaller virtual images and erect in nature gives one chance to use it as rear view mirrors

in cars and other it gives a clear view of all other people/cars which are placed behind.

some other times we can talk about its other properties.