Mirrors are an affordable and effective way to enhance beauty and create depth in any home. The right mirror can add more light to your space and increase the room’s aesthetic appeal. But how do you choose the ideal mirror for you?
A few different types of mirrors are used in various ways in our daily life. Whether you are considering adding a mirror to your home or office, using the right type of mirror influences its functionality and aesthetic appeal. Keep reading as we explore the definition, types, and working of mirrors.
What is a mirror?
A mirror is any surface that exhibits reflective properties. In other words, a mirror is capable of reflecting an image. When light from an object falls on the reflecting surface of a mirror, the incident ray is reflected from it. The light that hits a mirror is neither refracted nor diffused because the surface is smooth.
The difference between a mirror and other surfaces is that when light hits a rough surface, it is known as diffuse reflection. Still, when the surface is smooth such as in a mirror, the reflected light is in one single direction, also known as specular reflection. A mirror reflects every spectrum color, with no light being diffused or refracted. A true mirror keeps the lines, sharpness, contrast, colors, and other image properties intact.
Plane mirror vs. spherical mirrors
There are different types of mirrors. However, due to their wide applications, the two most common types are the plane mirror and the spherical mirror. The main difference between these two types of mirrors is how the light is reflected from the surface.
Since the surface of a plane mirror is flat and smooth, light reflects in a manner in which the angle of incidence (the angle at which the light hits the mirror) is equal to the angle of reflection (the angle at which the lights bounce off the mirror).
In contrast, a spherical mirror has a curved surface. As such, light reflection depends on the curvature of the mirror and the position of the object relative to the mirror.
What are the types of spherical mirrors?
Spherical mirrors can further be broken down into two types: concave and convex mirrors. To understand the differences between concave and convex mirrors, terminologies like the center of curvature, principal axis, and focal point are used.
Concave mirror vs. convex mirror
A concave mirror is a cutout of a curved reflective sphere inwards. A concave mirror is also known as a converging mirror because it converges parallel lights toward a focal point. The focal point is located on the principal axis of the mirror. The distance between the center of the mirror and the focal point is the focal length.
On the other hand, convex mirrors are also a cutout of a reflective sphere but one that is curved outwards. In other words, a convex mirror bulged outwards and away from the sphere’s center. A convex mirror is also a diverging mirror because it diverges light parallel to its principal axis.
Understanding the image formation by spherical mirrors
The images formed by the different spherical mirrors are different. As such, the way a concave mirror will behave is different from the way a convex mirror will.
- Image formation by concave mirrors
The position in which an object is placed relative to a concave mirror determines image formation. For example, placing an object after the focal point of a concave mirror forms a real, inverted, and diminished image between the center of curvature and the focal point. But when the object is placed before the focal point of a concave mirror, it gives a virtual, upright, and magnified image.
- Image formation by convex mirrors
Unlike a concave mirror, a convex mirror produces a virtual, upright, and reduced image every time, regardless of the object’s position relative to the mirror. Because a convex mirror does not have a real focal point but rather a virtual one, light appears to diverge from it, located on the same side of the mirror as the object.
Real-life examples of concave & convex mirror
The application of concave and convex mirrors are numerous. The mannerism of these spherical mirrors with light makes them useful in some real-life applications.
Uses of concave mirrors
- Headlight of a car: Because concave mirrors diverge lights, automakers use them to make car headlights focus the light in front of the road rather than being diffused. As such, the concave mirror helps to increase visibility while driving.
- Shaving mirror: Shaving mirrors are slightly concave because images forced after reflection are magnified, making it easier to make precise cuts.
Uses of convex mirrors
- Automobile side-view mirrors: You might have noticed the warning on car mirrors that says images on this mirror are closer than they appear. The reason is that the mirror is a convex mirror that produces a diminished image but has a wider field of view and reduces blind spots.
- Security mirrors at stores: Convex mirrors are also used in security spots because they allow personnel to see more of their surroundings. However, the image may appear distorted.
Frequently asked questions – FAQs.
• Does the law of reflection apply to spherical mirrors?
Despite how spherical mirrors behave, they still obey the law of reflection. For spherical mirrors, the normal is the line perpendicular to the mirror’s surface at the point of incidence. So, measuring the angle of incidence and the angle of reflection relative to the normal line are the same.
• Why does a concave mirror sometimes produce an inverted image?
The reason is that when an image is placed after the focal point, light reflecting from the image bends at different angles, causing the image to appear upside down.
• What is the difference between a refracted ray and a reflected ray?
When light is refracted, the light passes through a medium that changes the light’s direction and nature. In contrast, a reflected ray hits a surface and bounces off the surface.