What is a concave mirror and what is it used for?

A concave mirror is curved inward so that the incident rays of light are reflected and can be brought together. If the rays striking the mirror were parallel to each other, as they would be from a distant source, then the reflected rays converge at the focal point. Concave mirrors are typically used to focus waves, whether it is a microwave signal to a receiver, or light to an observer. They can produce real images.

If, however, the object is closer to the mirror than the focal point, as is often the case with a concave bathroom mirror, the image is virtual and upright. If you look at the reflection of a more distant object, like the bathroom wall, you’ll notice that it is upside down, or inverted. The wall is farther away from the mirror than the focal point, and its image is real.


This is a web preview of the "The Handy Physics Answer Book" app. Many features only work on your mobile device. If you like what you see, we hope you will consider buying. Get the App