Spherical Mirrors: Learn About Its Terms, Types, Uses

Mirrors came into existence almost 200 years ago in Germany. We are talking about the silver-glass mirrors first developed by German chemist ‘Justus von Liebig.’ In Physics, any surface that can reflect nearly any type of light beam is known as a mirror. Such surfaces are mostly smooth, polished, or lustrous. There are different shapes of mirrors. One of them is spherical in shape, known as Spherical Mirrors.

A spherical mirror forms two types of images, virtual and real images. These mirrors can form only these types of images because they have a constant radius of curvature and a consistent curve. Spherical mirrors are of two kinds- Concave mirrors and Convex mirrors. Continue reading this article to learn about the types of spherical mirrors, essential terms, and the uses of spherical mirrors.

Spherical Mirrors: Types

There are two types of spherical mirrors based on the surface painting:

1. Concave Mirrors: When the outer surface of the spherical mirror is painted or silvered, it gives rise to a type of mirror known as a concave mirror. Specifically, Concave mirrors are converging mirror surfaces because they converge light to the focus point.
   
2. Convex Mirrors: When the inner surface of the spherical mirror is painted or silvered, such types of mirrors are called convex mirrors. Specifically, Concave mirrors are diverging mirror surfaces because they reflect light on the outer surface.

Spherical Mirror: Terms

Spherical mirrors have many important terms related to their concepts. Students must remember these terms in order to understand spherical mirror concepts. So, all such terms and their explanations are as follows:

1. Pole (P): In spherical mirrors, the pole refers to the centre of the reflecting surface of the mirror. Alternatively, it is also the midpoint of the mirror.

2. Centre of Curvature (C): The centre of curvature of a spherical mirror is the centre of the hollow sphere glass of which the mirror is a part. 

3. Radius of Curvature: The radius of curvature refers to the radius of the hollow sphere glass of which the mirror is a part.

4. Principal Axis: The principle axis is an imaginary line from the centre of curvature passing through the pole or midpoint of the mirror.

5. Principal Focus or Focal Point (F): The principal focus is the point on the principal axis at which all the incident rays are parallel to the principal axis, and those rays close to it, actually appear to meet or converge after being reflected from the mirror.

6. Aperture: The aperture or linear aperture of a mirror is the diameter of the reflecting surface. Alternatively, it is the portion of a mirror from which the reflection of light usually takes place.

7. Focal Length (f): Focal length of a spherical mirror refers to the distance between the principal focus ‘F’ and the pole ‘P’ of the mirror. 

Uses of Spherical Mirrors

Now, let us understand the practical uses of the spherical mirrors in our day-to-day life. We will discuss the uses of both types of mirrors; concave mirrors and convex mirrors.

Uses of Concave Mirror

1. Reflecting telescopes employ concave mirrors to catch the reflections of distant celestial or astronomical objects.
2. Concave mirrors mostly make up the shaving mirrors to see the larger image of the face while shaving.
3. Solar furnaces use large concave mirrors to focus sunlight and produce heat. 
4. Torches, car headlamps, flashlights, and searchlights all use concave mirrors.
5. Dentists also use concave mirrors to see the backside of a patient’s teeth.

Uses of Convex Mirror

1. The Convex mirrors find wide uses in automobiles as rear-view (wing) mirrors.
2. These mirrors are most useful at curves of roads to give a view of the end of the road.
3. Convex mirrors are also typically present on the sides of automobiles, allowing the driver to observe approaching traffic or vehicles.

How to Effectively Practise?

Do you want to brush up on these physics concepts? Learn and practise on the Embibe app. Embibe is a unique learning and practise convenience for students. Utilise the practice feature of the Embibe Learning Outcomes app that allows you to practise tests and quizzes based on your knowledge of the topics, such as Spherical Mirrors. 

Moreover, it provides an intuitive platform to learn concepts through video lessons and summaries, which are available in the learning section of the Embibe app. Students can utilise these videos at their convenience to clear doubts. We are sure that these interactive video lessons will be helpful when you want to learn new things about Spherical Mirrors.

We hope that this article was of immense help to you. Follow Embibe for more intriguing articles like these. Happy Learning!