Profile
Settings
Refer your friends
Sign out
Image formation is a broad concept covering different kinds of lenses, mirrors, and surfaces.
Understanding how an image is formed through instruments like lenses and magnifying glasses is vital to get introduced to reflection and refraction. Moreover, it also acquaints us with the image formation on different types of mirrors.
In this article, we will be learning more about image formation through a different accommodation of lenses and exploring their properties.
What is Reflection?
By definition, the reflection of light means the bouncing back of a ray of light from a smooth polished surface.
In the case of reflection, we have an incoming ray towards an object, called the incident light ray, which lands upon the surface of an object.
After the incident ray hits the surface, it bounces back. This bounced ray is called the reflected ray.
An ideal example of reflection is the image formed in a mirror.
What is Refraction?
Refraction is an essential concept for understanding image formation better. It refers to the bending of light when it passes through a different medium. This bending of light is caused by the differences in density between the two mediums.
Refraction is one of the most common phenomena we observe in our day to day lives. From the formation of a rainbow in the sky to the twinkling stars we see every night, refraction is everywhere.
Due to refraction, we have instruments like magnifying glasses and lenses. Most importantly, it also allows us to focus light on the retina of our eyes.
Formation of an Image on a Mirror
A mirror follows the law of reflection as it produces an exactly opposite image of any object placed before it.
In this case, the object placed before the mirror is the source of incident rays and reflected rays form the image.
Based on this phenomenon, images are categorised as:
- Real images – Occurs when the ray of light intersects
- Virtual images – Occurs when the beam of light diverges from a point
Talking about the types of mirrors, we have two types of mirrors that include:
Plane Mirrors – A flat and smooth reflective surface that forms an upright virtual image of the same shape and size as the object.
Spherical Mirrors – A mirror with a consistent curve and a curvature radius that forms real and virtual images.
Spherical mirrors are further divided into concave and convex mirrors, which acquaints us with forming images on different surfaces.
Formation of Images in a Concave Mirror
Concave mirrors are curved inward in the middle.
When the inner part of a hollow sphere acts as a reflecting surface and its outer part is painted, it becomes a concave mirror. The formation of images in a concave mirror happens when light converges at a single point as it strikes and reflects from the mirror’s surface.
If the concave mirror is placed close to the object, it forms a magnified and a virtual image.
However, if the distance between the object and the mirror is increased, the size of the image is reduced, and it forms a small and real image.
Formation of Images in a Convex Mirror
Convex mirrors are curved outwards in the middle.
Quite the opposite of the concave mirrors, a convex mirror has a hollow sphere painted from the inside and the outer surface as the reflecting surface. The formation of images in a convex mirror happens when light diverges at a single point as it strikes and reflects from the mirror’s surface.
The images formed in a convex mirror are always virtual, erect and diminished.
Magnification
Magnification is another important concept related to the formation of images.
By the looks of it, everybody knows what magnification is. Magnification means making images seem bigger by using optical instruments like a magnifying glass.
Technically, magnification refers to the increased image size produced by spherical mirrors (concave and convex) with respect to the object size.
Denoted by the letter ‘m’, magnification is the ratio of the height of the image (denoted by h’) to the object’s height (denoted by h).
M = h’/h
Magnification is also related to the distance between the image and the object, which means it could be written as:
m = -v/u;
In this case, v is the distance of the image and u is the object’s distance.
Conclusion
Understanding the methods of forming images on different surfaces is essential to understanding this concept.
Image formation is applicable in our day to day lives in the form of vehicle headlights, torches, dentists, barbers, and so much more.
We hope this article on image formation and magnification was helpful to you and easy to understand.
