Introduction
In this world, we have both natural mirrors and man-made mirrors. Mirrors are a fascinating world by themselves. There are mirror museums where you have all shapes and kinds of mirrors which will make you appear tall, short, fat, thin and a variety of other things! Cartoons from our childhood would have their characters enter mirror worlds that were exactly the opposite of our real worlds.
The study of mirrors is one of the fundamental topics in physics. Do you see how closely this science is connected to our daily lives? Each morning and evening we see our reflection in the mirror at home - we tend to see not only the external self but also end up reflecting on what is going on inside of us. It is said smiling to yourself in the mirror, first thing in the morning fills your day with positivity!
Convex Mirror - Application and Working of Convex Mirror
Convex mirrors are also popularly called the fish eye mirror or diverging mirror. Its reflective surface bulges in the direction of the light source. A convex mirror has the ability to reflect all the light that falls on them in the outward direction. So, the type of image formed by these mirrors is always imaginary/virtual.
Also, due to the above property the size of the object’s image is smaller as compared to the actual object’s size. Therefore, a convex mirror is the most appropriate in those areas where large objects have to be viewed in a tiny size. This makes it easy for a person to view the image.
How does a Convex Mirror Differ from a Concave Mirror?
A convex mirror is also commonly called a curved mirror. Where the reflective surface of a concave mirror bulges towards the inward direction, in the case of a convex mirror it bulges in the direction where the light source is located.
The image of the object formed by a concave mirror is bigger than the actual size of the object. In the case of a convex mirror, it makes the object appear smaller in size. A concave mirror is used to magnify the image of the object but a convex mirror reduces the image size so that it gets accommodated easily in the mirror.
What are the Ways to recognize a Convex Mirror?
If you have to find which one is a convex mirror out of the different types of mirrors like a plane mirror, concave mirror, and convex mirror, then it can be done just by looking at the size of the image.
When you use a plane mirror, you will find that the size of the image generated by it will be the same as the actual size of the image. In the case of a concave lens, you will find that when the object is placed near the mirror, its image gets enlarged.
You will see an inverted form of the image when the object is kept at a far distance from the mirror. It is only a concave mirror that has the ability to generate an actual inverted image. The size of the image produced by a concave mirror is based on the screen placement. In the case of a convex mirror, it always generates a small-sized straight image.
Why is a Convex Mirror called a Diverging Mirror?
A convex mirror is given the name of a "diverging mirror". It is because of the behavior of the mirror that makes light rays diverge upon reflection. By this, it means that when a light ray is directed on this mirror, it enables the originally parallel light rays that form the beam to deviate/diverge after hitting the reflective surface of the convex mirror.
Understanding the working of a Convex Mirror
In a convex mirror, there is a point where light rays received from all the different directions meet. This helps in creating a focused beam. This point is referred to as the “focal point” or the focus. There is another term called “focal length” that determines the distance between the front of the convex mirror and the focal point.
Now let us understand the type of image formed by a convex mirror. A curved or convex mirror bends outward in the shape of a dome. It always forms an imaginary image. The reason behind it is that the “center of curvature” and the point of focus are both imaginary points in the mirror. Both of these points are unable to be reached.
It implies that the type of image made by this type of mirror can’t be projected on the screen. The image generated by the convex mirror is an upright virtual image that is relatively smaller in size than the size of the projected object.
Below are the major possibilities of a convex mirror for the object positioning in a convex mirror.
When an object is located at infinity
When the object lies at infinity, then a tiny image is produced at a principal focus point. This point is located behind the mirror. You will see that the image produced is virtual, highly diminished and erect.
When an object lies between the pole and infinity of the mirror
When an object lies between the pole and infinity of this mirror, then you will see a diminished form of an erect and virtual image. This image is created between focus and pole behind the convex mirror.
What are the Areas of Application of a Convex Mirror?
There are different functions performed by a convex mirror that makes it useful in a variety of applications. Let us see some of the important uses of convex mirrors.
Automobiles: Safety and efficiency are the two most essential requirements when you drive on the road. By providing a good overview to drivers about the rear and side view of the roads, and surroundings, help drivers to foresee risky situations and avoid accidents. The convex mirror is one of the important things that offer a clearer rear view of the road to ensure maximum safety all the time.
A convex mirror has broader fields of view as compared to reflective surfaces of concave and plane mirrors. Due to this, convex mirrors are used in forming side mirrors off an automobile. These mirrors provide a fish-eye view to the person who drives the automobile. This feature helps them to get a clear view of the rear area of the road easily.
The virtual image created of the object has a smaller size than its actual size. It provides a wide field view. Convex mirrors provide heightened safety for motor drivers on roads, alleys, and driveways where very little visibility is there.
Automated Teller Machines
Convex mirrors are kept close to the ATM or automated teller machine to permit the customers to figure out whether someone is standing behind them. This is used to ensure the security of the customers while they use an ATM. It ensures safety from the theft of withdrawals of cash or any other precious item. Also, it keeps the identity of the machine user safe and secure.
In-Camera
Some mobile phones come with a selfie camera built into them that aids users to capture a self-portrait shot.
Inside Buildings
Large hospitals, hotels, schools, offices, apartment buildings or stores use convex mirrors to allow people to view what goes around a corner. This helps in avoiding minor or major collisions.
In Sunglasses
Convex mirrors are used in developing a sunglass lens. The overall purpose is to reflect the sunlight away from the person who wears these glasses.
In the Magnifying Glass
Two convex mirrors when placed next to each other can form a magnifying glass.
In Street Light
A convex mirror is used as a street light reflector due to its ability to spread light rays over a larger region.
In Telescope
Convex mirrors are used in telescopes to see far off objects clearly in the form of point-sized images.
Production Process
Another important use of a convex mirror is in the work environment at the time of the production process. A convex mirror placed on the conveyor belt assists in viewing a product from varying angles.
This enhances the quality of the product by getting aware of any kind of production-based faults and improves the efficacy of production processes. This happens by eliminating the requirement to assess the quality of products on the conveyor belt.
FAQs on Convex Mirror
1. What is a convex mirror and how does its shape affect the path of light rays?
A convex mirror is a spherical mirror whose reflecting surface bulges outward, facing the source of light. This shape causes incident rays to diverge after reflection, making them appear to originate from a common point behind the mirror. The diverging property allows convex mirrors to provide a wider field of view than other types of mirrors.
2. How is the image formed by a convex mirror different from that of a concave mirror or a plane mirror?
The image formed by a convex mirror is always virtual, erect, and diminished (smaller than the object), regardless of the object's position. In contrast, a concave mirror can form real or virtual images that may be magnified or diminished, depending on the object's position. A plane mirror produces a virtual image that is the same size as the object and is laterally inverted.
3. Why are convex mirrors used as rear-view and security mirrors in everyday life?
Convex mirrors are used as rear-view mirrors in vehicles and for security because they offer a wide field of view. This allows drivers or observers to see more area compared to flat or concave mirrors. The diminished and erect images help monitor large spaces, making them ideal for safety in traffic, driveways, shops, and at ATMs.
4. What are the key properties of a convex mirror as per the CBSE 2025-26 syllabus?
The key properties of a convex mirror include:
- Diverging nature: Reflects light rays outward.
- Virtual focus: The focal point and center of curvature are located behind the mirror and are not physically accessible.
- Always forms virtual, erect, and diminished images.
- Wide field of view: Covers a larger area for observation compared to other mirrors.
5. Explain with examples the main applications of convex mirrors in daily and scientific contexts.
Common applications of convex mirrors include:
- Automobile rear-view mirrors: To provide drivers with a broad view of the road behind.
- Security mirrors: Used in shops, driveways, and ATMs for surveillance and safety.
- Street lamp reflectors: To spread light over a wider area.
- Telescopes: Reduce image size for a wide field of vision.
- Sunglass lenses: Reflect sunlight away from the eyes.
6. How can students identify whether a mirror is convex in a practical situation?
To identify a convex mirror, observe the following:
- The reflecting surface bulges outward.
- The image formed is smaller, erect, and virtual regardless of object distance.
- The mirror provides a wide field of view, displaying more area than a plane or concave mirror.
7. What happens to the image formed by a convex mirror when the object is placed at infinity versus when it is between the pole and infinity?
When an object is at infinity, a highly diminished, point-sized, erect, and virtual image is formed at the focus behind the mirror. When the object is placed anywhere between the pole and infinity, the image remains virtual, erect, and diminished, and appears between the pole and the focus behind the mirror.
8. Why can't the image formed by a convex mirror be projected onto a screen?
The image formed by a convex mirror is virtual, meaning light rays do not actually converge at the image location. Since the rays only appear to come from behind the mirror, the image cannot be projected onto a physical screen.
9. What conceptual mistakes do students often make regarding the focus and center of curvature in convex mirrors?
Students often believe the focus and center of curvature of a convex mirror are real, but both are virtual points located behind the mirror. These points are not physically accessible, unlike those in a concave mirror, and exist only as geometrical constructs for image formation analysis.
10. How does the focal length of a convex mirror influence its usage in design and technology?
The focal length of a convex mirror determines how much the mirror diverges light rays. A shorter focal length provides a wider field of view but a smaller image. Designers use mirrors with suitable focal lengths for applications like vehicle mirrors, security monitoring, and optical devices, balancing between field of view and image clarity.
