Concave Mirror
What does a concave mirror look like? In which things we use concave mirrors? People do not understand the use of a CM. However, concave mirrors are very important and their most common use is in flashlight and headlights.
What is a Mirror?
A mirror is an object that reflects the light in the same angle as it receives from the object. Also, the angle of incident is equal to the angle of reflection in a mirror. Besides, the reflected light is of the same intensity as the light projected.
Furthermore, the mirrors are of three types
- Plain Mirror
- Concave Mirror
- Convex Mirror
Working of Concave Mirror
A concave mirror is a type of mirror that is bent towards the inwards in the middle. In addition, on looking in this mirror, you will feel that you are looking in a cave. Besides, we use the mirror equation to deal with a concave mirror.
The equation for these mirrors determines how far or near the object is from the mirror and what is the size of the object is (large or small). \
Furthermore, the law of reflection still works for the surface of a concave mirror. But, the angle of incidence in the concave mirror is not equal to the angle of reflection.
Besides, the angle of reflection depends on the area on which the light hits. In addition, this helps the mirror to act as a lens of the camera that focuses the light to form an image.
Also, concave mirrors can focus real image that projects in the front of the mirror at the place where light focuses.
The image created by CM look like a floating image in the air. Also, you don’t have to stare in the mirror glass to see this object’s image.
Two concave mirrors placed upon each other then it will create an image of the object that appears to be floating in the air on the top side of the mirror.
Properties of a Concave Mirror
Before discussing the properties of a concave mirror we have to understand some point about the image formed by a concave mirror. Firstly, for a spherical mirror-like CM the focal distance is half of the radius of the focal length.
Secondly, the mirror reflects the ray of light from the centre on the same path. Lastly, the image form by CM can be real or virtual. So, the properties of the concave mirror are:
- If the object is put in between the focus and mirror- In that case, the image form on the surface is virtual and bigger than the object and of the same orientation as the object.
- If the object is put in between the centre of the mirror and focus point- In this case, the image formation by the mirror is real and bigger than the object. In addition, the image formation is also inverted.
- The object is kept two focal distance away from the mirror- In that case, the image will be real and inverted. Besides, the image formation is smaller in size.
Use of Concave Mirror
The usage of a concave mirror is very common in many household devices and equipment like shaving mirrors, flashlight, headlight etc. and bigger devices such as aircraft, telescope etc.
Solved Question for You
Question. Among the following which is an example of a concave mirror?
A. Side View Mirror
B. Common mirror of houses
C. Headlights
D. Optical instruments
Answer. The correct answer is C. Because option A and D are examples of a convex mirror and option B is an example of a plain mirror.
