Mirrors in Physics: Working, Types, and Everyday Uses

A Mirror is something we use almost every single day, without even noticing it! Whether you are getting ready for school, checking your hairstyle, or even looking at your reflection in a shiny object, mirrors help you see yourself clearly.

A mirror is simply a flat or curved surface that reflects light, allowing it to form an image of whatever stands in front of it. But have you ever wondered howa mirror manages to show such a perfect reflection? This article explains in simple words what mirrors are, the different types of mirrors, and how each type forms images simply and clearly. 

Table of Contents

• What is a mirror?
• How does Mirror Work?
• Important Terminologies Related to Mirrors
• Types of Mirrors

What is a Mirror?

Have you ever wondered how a simple piece of glass helps you check how you look, style your hair, or signal someone from far away? That magical object is a mirror. 

 

We can define a mirror as, 

“A mirror is a smooth and shiny surface that reflects light in such a way that it forms a clear image of an object in front of it.”

Most mirrors have a thin layer of shiny metal (aluminium or silver) coated on the back of a glass sheet. This metal layer is what actually reflects the light.

Do you know, the working of a mirror is totally based on the law of reflection, which states that the angle of incidence at which light hits the mirror is equal to the angle at which it bounces off, that is angle of reflection.
That’s how mirrors show us a perfect image of ourselves and everything around us!

How does Mirror Work?

Have you ever wondered what shiny smooth surfaces show clear reflections, but a white or other coloured wall doesn’t? Lets discuss

We already know that when light hits a surface, it can either be reflected or absorbed. Mirrors are special because they are designed to reflect almost all the light that falls on them. 

 

But what makes a mirror different from an ordinary flat surface? Its microscopic smoothness. 

Even though a wall or a piece of paper may look smooth to our eyes, they actually have tiny bumps and uneven parts. When light strikes such a rough surface, it scatters in all directions. This scattered bouncing of light is called diffuse reflection, which is the main reason why you don’t see your reflection on a wall.

Interestingly but a mirror has a surface that is polished that which is smooth even at the microscopic level. When light hits this smooth surface, it bounces back in one uniform direction, creating a clear image. This type of reflection is called specular reflection.

And this is the reason why only mirrors and other very smooth, shiny surfaces like mirrors can show you a proper reflection.

With that in mind, let’s discuss some important terminologies related to mirrors that will help you understand how they work even better.

Important Terminologies Related to Mirrors

1. An incident ray is a ray of light that first strikes the surface.
2. A reflected ray is the ray of light that bounces back after hitting the surface.
3. Normal is an imaginary line that is drawn at 90 degrees to the reflecting surface at the point where light hits.
4. Refracted Ray is a part of the incident ray that enters a second medium and bends due to the change in speed. 
5. Angle of Incidence is the angle between the incident ray and the normal
6. Angle of Reflection is the angle between the reflected ray and the normal. 
7. Angle of Refraction is the angle between the refracted ray and the normal in the second medium.

Now that you know these important terminologies, it will be much easier to understand the different kinds of mirrors and how they behave. 

Types of Mirrors

Mirrors come in three main types, and each one behaves differently based on its shape:

• Plane Mirrors
• Concave Mirrors
• Convex Mirrors

Concave and convex mirrors together are known as spherical mirrors because their reflecting surfaces are curved like a slice of a sphere. This curve is what gives them their unique properties.

Plane Mirror

A plane mirror is the simple, flat mirror you see every day, on your wall, in your bathroom, or on your cupboard door. 

 

But have you ever wondered how it shows your reflection so clearly? Here’s what happens:

• The image you see is virtual, which means you can see it, but you can’t project it on a screen.
• It appears upright and the same size as you.
• It is laterally inverted, your left looks like right, and your right looks like left.
• The image forms behind the mirror, at the same distance you stand in front of it.

That’s why when you step closer, your reflection also “comes closer,” and when you move back, it moves back too!

But, where are plane mirrors used?
Everywhere! You will find them in bathrooms, dressing rooms, shops, offices, cars, and even in decorative wall designs. They help you get ready, check your appearance, and brighten up rooms by reflecting light.

Read More: Reflection on a Plane Mirrors

Convex Mirrors

A convex mirror bulges outward, just like the back of a spoon.

Have you ever looked at your reflection on the curved back of a spoon? You will notice your face looks smaller; that’s exactly how a convex mirror works!

 

Because of its outward curve, a convex mirror always spreads out light. This gives it a wide field of view, meaning it can show more area than a flat mirror. Here is some unique image-forming properties. 

• The image formed is always virtual, upright, and smaller than the object.
• These mirrors are excellent for showing more area in a small space.

But where are convex mirrors used?

 Convex mirrors are commonly used as rear-view and side-view mirrors in vehicles, in hallways, parking lots, and shops to help observe wider spaces and improve safety. 

Read More: Uses of Convex Mirror

Concave Mirrors

 A concave mirror curves inward, just like the inside of a bowl or a spoon.

If you look at the inside of a shiny spoon, that’s exactly how a concave mirror looks!

 

Because of its shape, it can focus light at a single point, which gives it some unique image-forming properties. It can form real or virtual images, depending on where the object is placed. 

Let’s look at how the image formed when the object is placed at different positions in front of the concave lens.

Position of the Object	Position of the Image
At Infinity	Highly diminished, real and inverted
Beyond the Centre of Curvature	Diminished, real and inverted
At the Centure of Curvature	Same size as that of the object, real and inverted
Between the Centre of Curvature and Principal Focus	Enlarged, real and inverted
At Principal Focus	Highly enlarged, real, and inverted
Between the principal Focus and Pole	Behind the mirror, highly enlarged, virtual and erect

But where are concave mirrors used?

Concave mirrors are used in shaving and makeup mirrors, headlights of vehicles, solar cookers, torches, microscopes, and telescopes because they can focus and direct light effectively.

Read More: Uses of a Concave Mirror

So far, we have seen that mirrors are smooth reflecting surfaces that help form images by reflecting light. We also studied how mirrors work, important terms related to reflection, and the three main types of mirrors, plane, concave, and convex mirrors, along with their image properties and practical uses in daily life.