• Skip to main content
  • Skip to secondary menu
  • Skip to primary sidebar
  • Skip to footer

CBSE Tuts

CBSE Maths notes, CBSE physics notes, CBSE chemistry notes

  • NCERT Solutions
    • NCERT Solutions for Class 12 English Flamingo and Vistas
    • NCERT Solutions for Class 11 English
    • NCERT Solutions for Class 11 Hindi
    • NCERT Solutions for Class 12 Hindi
    • NCERT Books Free Download
  • TS Grewal
    • TS Grewal Class 12 Accountancy Solutions
    • TS Grewal Class 11 Accountancy Solutions
  • CBSE Sample Papers
  • NCERT Exemplar Problems
  • English Grammar
    • Wordfeud Cheat
  • MCQ Questions

Spherical Mirrors – Types and Applications

Contents

The study of Physics Topics can help us understand and solve real-world problems, from climate change to medical imaging technology.

Some Important Terms Related To Spherical Mirrors

All the mirrors are not straight like plane mirrors. Some of the mirrors are curved mirrors. The common example of a curved mirror is a spherical mirror. A spherical mirror is that mirror whose reflecting surface is the part of a hollow sphere of glass. The inside surface of a hollow sphere of glass is bent-in’ or ‘concave’ but the outside surface of a hollow sphere of glass is ‘bulging-out’ or ‘convex So the spherical mirrors are of two types:

  1. Concave mirror, and
  2. Convex mirror.

We will discuss both the types of spherical mirrors in detail, one by one.

A concave surface means ‘bent-in’ surface. A concave mirror is that spherical mirror in which the reflection of light takes place at the concave surface (or bent-in surface). A concave mirror has been shown in Figure(a).
Spherical Mirrors - Types and Applications 1
The concave surface of this mirror is on its left side which has been marked A. The reflection of light takes place from this concave surface. The back side of concave mirror has a silver coating which is protected by a layer of red paint. The back side of concave mirror is represented by drawing short, oblique lines.

In Figure(a), the back side of concave mirror has been marked B. Actually, Figure (a) shows a concave mirror as it looks from the side. That is, Figure (a) gives us the side view of a concave mirror. When we look at a concave mirror from the front, it appears like a thin piece of spherical glass whose front surface is shining and bent inward (whereas back surface is covered with a paint and bulging outward). The front view of a concave mirror is shown in Figure (b).

A convex surface means ‘bulging-out’ surface. A convex mirror is that spherical mirror in which the reflection of light takes place at the convex surface (bulging out surface). A convex mirror is shown in Figure (a).
Spherical Mirrors - Types and Applications 2
The convex surface of this mirror is on its left side which has been marked B. The reflection of light takes place from this convex surface. The back side of a convex mirror has a silver coating which is protected by a layer of paint. The back side of convex mirror is represented by drawing short, oblique lines.

In Figure (a), the back side of convex mirror has been marked A. Actually, Figure (a) shows how a convex mirror looks when seen from the side. If we look at a convex mirror from the front, it appears to be a thin piece of spherical glass whose front shining surface is bulging outward (but the back surface covered with paint is bent inward). The front view of a convex mirror is shown in Figure (b).

From the above discussion we conclude that a mirror whose reflecting surface is ‘bent inward’ is a concave mirror whereas a mirror whose reflecting surface is ‘bulging outward’ is a convex mirror. A shining steel spoon represents both, a concave mirror as well as a convex mirror. The front side (or inner side) of a spoon is bent inward, so the front side of a shining spoon represents a concave mirror (see Figure).
Spherical Mirrors - Types and Applications 3
The back side (or outer side) of a spoon is bulging outward, so the back side of a shining spoon represents a convex mirror (see Figure). If we look into a shining steel spoon, we will find that the front and back of a spoon give different types of images of our face. This is because the front and back of a shiny spoon represent two different types of mirrors (concave mirror and convex mirror). Please note that just like plane mirror, the spherical mirrors (like concave mirror and convex mirror) also work on the reflection of light from their surfaces.

Why are Concave and Convex Mirrors Called Spherical Mirrors

Concave mirror and convex mirror are called spherical mirrors because they can be considered to be small parts of a hollow sphere of glass. This will become more clear from the following activity.

Activity 2

In this activity we will give the example of a ‘hollow sphere of rubber’ which is a ‘hollow rubber ball’ because it is easy to cut a rubber ball than a glass ball. Take a hollow rubber ball and cut a small portion of it with a knife very carefully (see Figure).
Spherical Mirrors - Types and Applications 4
The ‘inner surface’ of the small part of the cut ball is ‘concave Such a surface makes a concave mirror. The ‘outer surface’ of the small part of the cut ball is convex Such a surface makes a convex mirror. This activity shows how the real concave mirror and convex mirror can be considered to be small pieces taken from large, hollow sphere of glass.

Concave Mirror is a Converging Mirror

Light rays coming from a distant object are parallel to one another. Suppose a beam of parallel rays of light falls on a concave mirror from the left side (as shown in Figure). We will see that after reflection from the concave mirror, the parallel rays of light are getting closer together (or coming together).

When the rays of light come closer, we say that the rays of light are converging. The concave mirror reflects the parallel rays of light in such a way that, after reflection, all the rays converge (or meet) at one point called ‘focus in front of the mirror (see Figure).
Spherical Mirrors - Types and Applications 5
The focus of a concave mirror is a point in front of the mirror at which parallel rays of light converge after reflection from the concave mirror. Focus (also called principal focus) is denoted by the letter F. The distance from the focus up to the concave mirror is called focal length of concave mirror (see Figure).

The focal length is denoted by the letter f The focus of a concave mirror is in front of it. The focus of a concave mirror is ‘real’ because light rays actually pass through it, Since a concave mirror converges a beam of parallel light rays, therefore, a concave mirror is also known as a converging mirror.

Convex Mirror is a Diverging Mirror

Suppose a beam of parallel rays of light falls on a convex mirror from the left side (as shown in Figure). We will see that after reflection from convex mirror, the parallel rays of light are spreading out (or going away from one another). When the parallel rays of light spread out, we say that the rays of light are diverging. We can now say that a beam of parallel light rays diverges (spreads out) after reflection from a convex mirror (see Figure).
Spherical Mirrors - Types and Applications 6
Since the parallel rays of light diverge (spread out), they cannot meet at a point in front of the convex mirror. To a person looking into the convex mirror, the reflected rays appear to be coming (or spreading) from a single point F behind the convex mirror (see Figure). The point F is called focus of convex mirror.

The focus of a convex mirror is a point behind the mirror from which the parallel rays of light falling on convex mirror appear to diverge after reflection from convex mirror. The distance from focus up to the convex mirror is called focal length of convex mirror (see Figure). The focus of a convex mirror is behind it.

The focus of a convex mirror is ‘virtual’ because light rays do not actually pass through it. Since a convex mirror diverges a parallel beam of light rays, therefore, a convex mirror is known as a diverging mirror.

Primary Sidebar

NCERT Exemplar problems With Solutions CBSE Previous Year Questions with Solutoins CBSE Sample Papers
  • The Summer Of The Beautiful White Horse Answers
  • Job Application Letter class 12 Samples
  • Science Lab Manual Class 9
  • Letter to The Editor Class 12 Samples
  • Unseen Passage For Class 6 Answers
  • NCERT Solutions for Class 12 Hindi Core
  • Invitation and Replies Class 12 Examples
  • Advertisement Writing Class 11 Examples
  • Lab Manual Class 10 Science

Recent Posts

  • Understanding Diversity Question Answer Class 6 Social Science Civics Chapter 1 NCERT Solutions
  • Our Changing Earth Question Answer Class 7 Social Science Geography Chapter 3 NCERT Solutions
  • Inside Our Earth Question Answer Class 7 Social Science Geography Chapter 2 NCERT Solutions
  • Rulers and Buildings Question Answer Class 7 Social Science History Chapter 5 NCERT Solutions
  • On Equality Question Answer Class 7 Social Science Civics Chapter 1 NCERT Solutions
  • Role of the Government in Health Question Answer Class 7 Social Science Civics Chapter 2 NCERT Solutions
  • Vital Villages, Thriving Towns Question Answer Class 6 Social Science History Chapter 9 NCERT Solutions
  • New Empires and Kingdoms Question Answer Class 6 Social Science History Chapter 11 NCERT Solutions
  • The Delhi Sultans Question Answer Class 7 Social Science History Chapter 3 NCERT Solutions
  • The Mughal Empire Question Answer Class 7 Social Science History Chapter 4 NCERT Solutions
  • India: Climate Vegetation and Wildlife Question Answer Class 6 Social Science Geography Chapter 8 NCERT Solutions
  • Traders, Kings and Pilgrims Question Answer Class 6 Social Science History Chapter 10 NCERT Solutions
  • Environment Question Answer Class 7 Social Science Geography Chapter 1 NCERT Solutions
  • Understanding Advertising Question Answer Class 7 Social Science Civics Chapter 7 NCERT Solutions
  • The Making of Regional Cultures Question Answer Class 7 Social Science History Chapter 9 NCERT Solutions

Footer

Maths NCERT Solutions

NCERT Solutions for Class 12 Maths
NCERT Solutions for Class 11 Maths
NCERT Solutions for Class 10 Maths
NCERT Solutions for Class 9 Maths
NCERT Solutions for Class 8 Maths
NCERT Solutions for Class 7 Maths
NCERT Solutions for Class 6 Maths

SCIENCE NCERT SOLUTIONS

NCERT Solutions for Class 12 Physics
NCERT Solutions for Class 12 Chemistry
NCERT Solutions for Class 11 Physics
NCERT Solutions for Class 11 Chemistry
NCERT Solutions for Class 10 Science
NCERT Solutions for Class 9 Science
NCERT Solutions for Class 7 Science
MCQ Questions NCERT Solutions
CBSE Sample Papers
NCERT Exemplar Solutions LCM and GCF Calculator
TS Grewal Accountancy Class 12 Solutions
TS Grewal Accountancy Class 11 Solutions