Uses of Convex Lens
A convex lens is a lens that converges ray of light that is traveling parallel to its principal axis. A convex lens is relatively thick at the middle and thin at the upper and lower edges. The edges of the rays curved outward rather than inward. In this article, you will learn about the convex lens and uses of convex lens.
As the ray of light reaches the lens, the rays become parallel to each other. As soon as rays reach the glass surface, they refract according to the effective angle of incidence at that point of the lens. The curved surface of the lens results in the refraction of light rays at different degrees.
The outermost ray will refract the most. Another name of a convex lens is a converging lens or positive lens that is thicker in the middle. A convex lens converges the light rays that pass through it. In other words, the rays brought closer to each other. We will discuss the uses
Types of Convex Lens
On the basis, of the curvature of the two optical surfaces lenses are of two types biconvex and convex-concave. If the lens is biconvex or plano-convex, the lens is positive or converging. A lens is biconvex if both surfaces of the lens are convex.
Biconvex lenses are used in the manufacture of magnifying glasses. If each surface of the lens has an equivalent radius of curvature, the lens is known as an equi-convex biconvex. If one of the surfaces of the lens is flat, the lens is plano-convex.
A lens having one surface convex and one surface concave side is a convex-concave lens. Convex-concave lens is used in the manufacture of corrective lenses.
Some Common Uses of Convex Lens
Some of the uses of convex lens are:
The Convex Lens in Magnifying Glasses
Most common use of convex lens is in a magnifying glass. As the light rays enter the convex lens present in the magnifying glass, these rays become focused on a specific focal point in front of the center of the lens. Furthermore, if the magnifying glass is at an optimal distance, this generates the maximum magnification of the object.
The Convex Lens in Eyeglasses
A person can have problems like farsightedness or nearsightedness as the eye lens fails to focus the light on the retina properly. A person who is suffering from farsightedness, the image formed by the lens is far behind the retina.
In addition, this makes a person difficult to see near objects, as their lens is not capable to focus the image in a proper manner on the retina. We can cure this by using a convex lens placed in front of their eye.
Besides, the convex lens bends the light rays that reduce the length of the focal point and the light focuses on the retina in a proper manner.
The Convex Lens in Cameras
In a camera, we use a convex lens because it focuses on an image as well as magnify the image of the object. Also, the camera lens consists of a convex lens followed by a concave lens, followed by a second convex lens. The first lens controls the magnification level of the image by moving away from or towards the object.
Convex Lens Uses in Microscopes
In a microscope, we use a convex lens because convex lens magnifies images. Microscopes generate extremely magnified images of very small objects for this purpose convex lens are very useful. Moreover, simple microscopes mostly consist of three lenses.
However, among the three lenses, the lens present at the end of the microscope produces an inverted and magnified image.
Solved Question for You
Q: What happens to the focal length if we want to increase the magnifying power of a telescope?
- Increase the focal length of the objective lens.
- A decline in the focal length of the objective lens.
- Increase the focal length of the eyepiece lens.
- Decrease the focal length of the eyepiece lens.
Ans. D.
We can determine the magnification of the instrument by dividing the focal length of the eyepiece into the focal length of the objective lens.
If we increase the focal length of the objective lens, the length of the tube also increases. Therefore, to increase the magnification of the telescope we have to decrease the focal length of the eyepiece.
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