Everything You Need to Know About Concave Mirrors: Definition, Properties, and Examples

CNN Indonesia

Tuesday, 23 April 2024 07:00 WIB

Jakarta, CNN Indonesia —

A concave mirror is a type of mirror with a curved inner surface. Thanks to these features, concave mirrors have advantages, one of which is as a tool optics.

To better understand what a concave mirror is, consider the definition, features and device examples a mirror under it.

What is a concave mirror?

Quoting from the book Simple and Practical Learning Physics, a concave mirror is a mirror that has an inwardly curved or concave surface. Its curved shape like the inside of a ball makes a concave mirror converge or gather light.

The shape of the surface of a concave mirror is different from the shape of a flat mirror or a convex mirror. Plane mirrors have a flat surface and convex mirrors have a surface that curves outwards.

A concave mirror has the characteristic that the image is always virtual, vertical and reduced.

Concave mirror properties

There are several features that distinguish concave mirrors from other types of mirrors such as flat and two-dimensional mirrors. These are the properties of a concave mirror.

1. Comforter

Quoting from the book Integrated Science: Biology, Chemistry, Physics Class VIII Volume II, a concave mirror has converging properties, which means it gathers light to a focal point. The center of the circle that is part of the mirror is called the center of curvature.

At the same time, the line that passes through the center of the mirror and the center of curvature is called the principal axis. Any light that comes parallel to the main axis will be reflected.

After that, these rays cross at a point called the focus, so the concave mirror can collect light that comes parallel.

2. The focal value of a concave mirror is always positive

Quoting from the book Optics – Preparing for the Physics Olympiad by Prof. Yohanes Surya, concave mirrors are often called positive mirrors because of their ability to focus light to a precise point.

A bowl-shaped concave mirror with an inner curved surface reflects light and focuses it onto a precise focal point in front of the mirror. This creates realistic and enlarged images.

3. Shadow

The nature of the image of an object formed by a concave mirror depends on the position of the object relative to the mirror. If the object is close, the image is straight, false (virtual), and larger than the original.

But if the object is far from the concave mirror, the image is real or real and indirect.

An example of a concave mirror

Here are examples of the use of concave mirrors.

1. myopia glasses

Myopic glasses or myopia (near-sighted) glasses use concave lenses because they can focus the image precisely on the retina of the eye.

This is because myopia glasses have an inner curve or curve that causes the light passing through the glass to meet at one focal point, resulting in clear vision or vision.

2. Mouth mirror

Dentists use an oral mirror to examine the patient’s teeth and mouth using a concave mirror. With a long handle, this mirror allows you to reach inside the patient’s mouth.

At the same time, a concave mirror allows it to reflect light and create a larger image of areas of the mouth that are difficult to see.

3. Center

Flashlights are considered concave mirrors because their design uses the principle of refraction of light by concave mirrors to produce focused light. In a flashlight, a lamp or light source is placed near the center of a concave mirror.

4. Vehicle lights

Vehicle headlights include concave mirrors because they use the principle of light refraction by a concave mirror to produce a directional light pattern. In vehicle headlights, the light source is placed near the focus of the concave mirror.

That is the definition, properties and examples of concave mirrors. Hope it is useful.

(can/fef)