Types of Spherical Mirrors

Spherical Mirrors are of two types, namely:

1. Concave Mirrors
2. Convex Mirrors

The two types of spherical mirrors are discussed in detail:

Concave Mirror

A spherical mirror of which the reflecting surface is curved inwards which means that it faces towards the centre of the sphere is known to be a concave mirror. The back of the mirrors is always shaded so that reflection can take place only from the inward bulged surface. 

The surface of the spoon which is curved inwards can be approximated to a concave mirror. It is also known as the converging mirror as the ray of light after bouncing back from it appears to converge at some points where we can obtain a real, inverted, and enlarged or diminished image based on the location of the object.

Uses of Concave Mirror

• Converging mirrors are most widely used in shaving because they have reflective and curved surfaces.
• A concave mirror is used in the ophthalmoscope
• These mirrors are also widely used in making astronomical telescopes. In an astronomical telescope, a converging mirror of a diameter of about 5 meters or more is used as the objective.
• Converging mirrors are widely used in headlights of automobiles and in motor vehicles, torchlights, railway engines, etc. as reflectors.
• Large converging mirrors are used to focus the sunlight to produce heat in the solar furnace.

Convex Mirror

A spherical mirror having its reflecting surface curved outwards is known to be a convex mirror. The back of the mirror is shaded so that reflection only takes place from the outward bulged part. The surface of the spoon which is bulged outwards can be assumed to be a convex mirror. It is also known as a diverging mirror as the light after reflecting through its surface diverges to many directions but appears to meet at some points where the virtual, erect image of diminished size is formed.

Uses of Convex Mirror

• Convex mirrors are used inside buildings so that people can see all around the building at once.
• The convex mirror is used in vehicles. Convex mirrors are commonly used as rear-view mirrors in the case of automobiles and vehicles because they can diverge light beams and make virtual images.
• These mirrors are mostly used for constructing magnifying glasses. In industries, to construct a magnifying glass, two convex mirrors are placed back to back.
• Diverging mirrors are also used for security purposes in many places. They are placed near ATMs to let the bank customers check whether someone is behind them or not.
• Convex mirrors are also widely used in various other places for example streetlight reflectors because they can spread light over bigger areas.

Check: Real Life Applications of Concave Mirror

Spherical mirrors are generally constructed from glass. A spherical surface is a part cut from a hollow sphere. This curved surface of the glass has a silver coating on one side and a polished surface on the other, where the reflection of light takes place. The term “convex mirror” refers to a mirror where the reflection occurs at the convex surface, and the term “concave mirror” refers to a mirror where the reflection occurs at the concave surface. The passenger-side wing mirrors of automobiles are the most common examples of convex mirrors.