Mirrors and Types of Mirrors

Terms Related to Mirrors

• Incident ray: It is defined as a ray of light that hits the surface.
• Reflected ray: It is defined as the ray of light that is reflected back after hitting the surface.
• Normal ray: It is defined as the ray that is 90° to the surface or the ray which is perpendicular to the reflecting surface.
• Refracted ray: It is defined as the incident ray which passes through a second medium resulting in the change of direction.
• Angle of incidence: It is defined as the angle between the incident ray and the normal at which the incidence occurs.
• Angle of reflection: It is defined as the angle between the reflected ray with respect to the normal at which the reflection occurs.
• Angle of refraction: It is defined as the angle between the refracted ray and the normal at which the refraction occurs.

Types of Mirrors

Following are the types of mirrors that are most widely used:

Plane mirror:

The images formed from a plane mirror are the reflected images in their normal proportions but reversed from left to right. These are the most widely used mirrors.

Read More: Plane Mirror

Convex mirror:

These are the spherical mirrors that are curved outward and the image obtained is virtual, diminished and erect for a real object.

Concave mirrors:

These are the spherical mirrors that are curved inward and the image obtained from these mirrors depends on the placement of the object.

Following is the table explaining the images obtained based on their placement:

Placement of the object	Image obtained
Placed at infinity	Highly diminished, real and inverted
Placed beyond the centre of curvature	Diminished, real and inverted
Placed at the centre of curvature	Same size as that of the object, real and inverted
Placed between the centre of curvature and principal of focus	Enlarged, real and inverted
Placed at principal focus	Highly enlarged, real and inverted
Placed between the principal of focus and the pole	Image is obtained behind the mirror, highly enlarged, virtual and erect

How Does a Mirror Work?

We know that when a light ray falls on the reflecting surface, it gets reflected. We also know that light is energy and energy can either be reflected or absorbed. Here, mirrors reflect light energy.

The reason why only mirrors are reflective and not the other flat white surface is because the mirror is smooth at a microscopic level. When the light energy hits the rough surface, the light bounces back in all directions and this is known as diffuse reflection. But for a smooth surface, the bouncing back of light happens in one direction and is known as specular reflection.

You may also want to check out the topics given below!

• Mirror Formula For Spherical Mirrors
• Spherical Mirror: Concave And Convex Mirror
• Reflection Of Light In A Mirror: Lateral Inversion

Watch the video to understand the differences between concave mirrors and convex mirrors.

Frequently Asked Questions – FAQs

Q1

What are concave mirrors?

Concave means rounded or hollow like the interior of a circle or sphere, they are also called converging mirrors.

Q2

What are convex mirrors?

Convex means rounded or curved like the exterior of a circle or sphere, also they are called a fish eye or diverging mirror.

Q3

What is a mirror?

A mirror is a reflective surface that bounces off light, producing either a real image or a virtual image. When an object is placed in front of a mirror, the image of the same object is seen in the mirror.

Q4

Define the Refracted ray.

It is defined as the incident ray which passes through a second medium resulting in a change of direction.

Q5

Define the Reflected ray.

It is defined as the ray of light that is reflected back after hitting the surface.

Watch the video and revise all the important concepts in the chapter Light Reflection and Refraction Class 10

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