Convex Mirror

Definition: What is Convex Mirror?

A convex mirror is a curved mirror that forms a part of a sphere and designed in such a way that light falling on its shiny surface diverges upon reflection. Hence, it is also called a diverging mirror. It cannot be used to produce real images. The image produced by a convex mirror is called a virtual image. It is formed behind the mirror, upright, and diminished but increases in size up to the object size as the object approaches closer to the mirror. This virtual image is created by extending the reflected rays backward.

Convex Mirror

Ray Diagram for Convex Mirror

Terms Used in Convex Mirror Imaging

Incident ray – The ray of light that is incident on the surface
Reflected ray – The ray of light that is reflected from the surface
Center of curvature – The center of the sphere from which the convex mirror has been constructed
Radius of curvature – The radius of the sphere from which the convex mirror has been constructed
Pole – The mid-point of the convex mirror
Principal axis – An imaginary line that connects the pole and the center of curvature
Focus – A point on the principal axis where rays of light that are parallel to the axis appear to diverge from
Focal length – The distance between the pole and the focus and is one-half of the radius of curvature
Object distance – The distance between the object and the pole
Image distance – The distance between the image and the pole

Convex Mirror Ray Diagram

Applications of Convex Mirrors

As side view mirrors in cars, buses, and trucks because the image formed is upright and small thus giving a wide field of view of the area toward the side of and behind the vehicle
As a security device in supermarkets, grocery stores, and convenient stores since the convex mirror gives a broad view of the area around corners
At corners on a road so that drivers can see the incoming vehicles and avoid a collision
As a safety device in warehouses, where workers can see incoming forklifts and vehicles
As security device in ATM since the user can see the area behind them
As street light reflectors because the reflected light can spread over a large area