Difference Between Concave and Convex Mirror

Mirror

A mirror is considered a reflective surface that can bounce off light and is capable of generating images that can be either real or virtual.

If there is an object placed in front of the mirror then the image of that object is visible on the mirror. An object placed in front of a mirror is considered a source and it consists of incident rays. On the other hand, an image can be produced by reflected rays. An image that is said to be real or virtual can only be decided based on light interaction. When the rays of light intersect, then the image formed is real. Meanwhile, a virtual image can occur only when there is an apparent divergence of rays from that particular point.

A ray diagram is one sort of diagram which can potentially help us in tracking the light path for an observer to visualize a point on the image. To demonstrate the incident and reflected ray, these ray diagrams use lines that contain arrows. This can help the observer trace the direction of light while traveling.

Furthermore, mirrors are broadly classified into two different types and are made into various kinds of shapes for various amounts of purposes. The two most fundamental mirror types are given as follows -

• Plane mirrors
• Spherical mirrors

Plane mirror

A plane mirror is a type of mirror which is flat in structure and possesses a smooth reflective surface. This mirror is capable of forming the virtual image of an object with the same shape and size. It is because the image formed is reflecting the object.

Spherical mirror

Spherical mirrors are considered to have consistent curves as well as a constant radius of curvatures. An image that can be formed by a spherical mirror can either be real or virtual. Moreover, there are two different types involved while talking about a spherical mirror. They are

• Concave mirror
• Convex mirror

Spherical mirrors contain curved surfaces which are painted on either one of the sides. When an inward surface of a spherical mirror is painted, then this type of mirror is considered a convex mirror. In the meantime, when the outward surface of the spherical mirror is painted, this mirror is called a concave mirror.

Concave mirror

When a hollow sphere is allowed to be cut in two equal parts and if the outer surface of the cut part is coated with paint, then it becomes a spherical mirror that contains an inner reflecting surface. These kinds of mirrors are termed concave mirrors.

Characteristics of concave mirrors

• The image which is generated by a concave mirror can be of any size namely large or small and it can be either real or virtual.
• A magnified image is obtained if this concave mirror is located close to an object. This can be considered as a virtual image.
• Concave mirrors are termed converging mirrors because light converges at a certain point when it is made to strike. This can be reflected from a surface contained in a concave mirror called the reflecting surface.
• A real image would be formed if we increase the distance between the object and the mirror. This is because when they are being kept far away from each other, the image that appeared is very small in size.

Image formation by a concave mirror

While shifting the object’s position from the mirror, various images are being generated. Different kinds of images are produced when the object is placed:

1. At infinity
2. At the center of curvature
3. Beyond the center of curvature
4. At the principal focus
5. Between pole and principal focus
6. Between principal focus and center of curvature

Convex mirror

When the hollow sphere’s cut part is coated inside with the paint, its reflecting surface can be determined as its outer surface. This type of mirror is described as a convex mirror.

Characteristics of a convex mirror

• A convex mirror can be considered a diverging mirror. This is because the convex mirror keeps on diverging the light whenever they are made to hit on its reflecting surface.
• Convex mirrors are highly capable of forming virtual as well as dimensional images no matter what the distance is, between the object and mirror.

Image formation by a convex mirror

The following are the types of images that can be formed by convex mirrors -

• A virtual image is capable of forming between the focus and pole of the convex mirror when an object is located at a specific or finite distance from that of the mirror. Here, the size of the image formed is smaller than that of the actual object.

NCERT Solutions For Class 10 Science Chapter 10 Light Reflection and Refraction introduces students to the different types of mirrors including concave, convex mirrors, concave and convex lens along with the difference between them.