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Why does a convex lens converge the rays that fall on it and a concave lens diverge the rays that fall on it?
Wiki User
∙ 15y ago
Better to understand how the shapes of the wavefronts of light change when they pass through the lens(concave or convex) in terms of Huygens Principle? The simple answer is that light travels in a straight line in any given medium. A medium could be anything light can pass through like air, vacuum, water, glass, plastic. Each medium has its own 'refractive index' which is a physical property of the material that varies the speed of light within a medium. Light travels slower in glass than it does in air for example. Light bending or refraction occurs as light passes the boundary of one medium into another. When viewing light from an object through a lens, that light passes from the object through air to the lens material and back into the air before reaching they observers eye.
Light rays entering the front convex or concave surface of a lens are refracted (bent) by the refractive index of the lens to a new path through the lens material. As light leaves the lens material it is bent again as it reenters the air. The extent that light rays bend depends on the lens material and the curvature of the lens surfaces. Light entering a convex lens is refracted toward a focal point on the other side of the lens. Light at the edges bends more than light passing through the center of the lens, however all rays converge at the focal point. If an observer were to place their eye just in front of the focal point the image would appear larger and in the same orientation. If an observer places their eye beyond the focal point the image appears inverted.
Light entering a concave lens is refracted away from a focal point making the image appear smaller.
Wiki User
∙ 15y ago
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Examples of concave and convex mirrors?
Convex means rounded or curved like the exterior of a circle or sphere. Also called as fish eye or diverging mirror. The mirror coating of the concave mirror is on the outside of the spherical surface. In concave mirrors, the center of curvature and the reflecting surface fall on the same side of the mirror.
How is an image seen in a plane mirror with the image in a convex mirror different?
Concave: a curved like a segment of the interior of a circle or hollow sphere; hollow and curved Convex:having a surface that is curved or rounded outwards plane-a flat mirror
Can a concave lens form a real image?
Never. Since the rays coming from a real object will always be diverging. The action of a concave lens is diverging action. Hence the already diverged rays will be dirverged further. Hence no chance of convergence. Only converging rays would form a real image. Hence the answer, NEVER.
What is the nature of eye lens of human eye and that of the image formed at the retina of the eye by it?
our eye has convex lens which has got the power of converging image . so when the light fall on the convex lens the sensory nerve of our eye immediately send electrical impulse to the mind then the mind make the clear and virtual image .or say when convex lens converge the falling light , the convex lens have a focus point which is retina at where all the light rays focused and images is formed .
What type of lens is used to correct nearsighted vision?
Using concave lens the short sight problem could be rectified. Near sighted person cannot see the things far away. He can see things only so near to his eyes. The ray coming from the far object would form an image just before retina since the eye ball is elongated horizontally. So to make the image to move backward and fall on the retina, a concave lens is used to diverge the ray and finally the image would fall on the retina. Thus the remedy is possible with concave lens.
What is concave len explain in detail?
In case of concave lens the edges will be thicker compared to the central part. Whereas the convex lens has edges so thin compared to the central part. Concave lens would have only divergence effect. Parallel beam of light falling on one side of the concave lens after refraction would come out from the other side diverging out and so they appear to come from a point on the incident side of lens. So no real image is obtained. Thus the image will be a virtual image. If converging rays fall on the concave lens after refraction may be still converging but it convergence will be reduced a little bit and so instead forming a real image nearby the concave lens it will be formed somehow far away from the lens.
Should a short sighted person use a concave or convex lens?
This is a lens which is designed to help someone who has problems seeing at distance (myope), the light rays going into your eye are not hitting the fovea (the part of the eye located on the retina which allow you to see clearly) in the proper place, these rays are falling in front of the fovea, so by using a concave ( a minus lens) lens, this moves these light rays by diverging them and moving them back to the fovea which allows for clear vision at distance. At least this is how a concave lens is used optically speaking.this is from winter006: concave mirrors are used in stores and gas stations to see a wider area of the store.It's also called , a Diverging Lens .It is thinnest in the centre and spreads light out , so it gives a diminished image .
How incident rays refracted by a convex lens?
By convex lens, rays fallen would be definitely converged hence named as converging lens. If rays fall parallel to the principal axis after refraction they would be converged at a point known to be the principal focus of the lens. If rays go in diverging state as the source is in between its F and O, optic centre then they would appear to come from the same side and so we get a virtual enlarged image. This is what a palmologist does with a lens to read the lines on the palm. Optic centre is the point on the lens through which as rays pass then it goes unrefracted or undeviated.
How many diagonals does a concave hexagon have?
A concave Hexagon is that hexagon which has one of its internal angle greater than 180 degrees. It can have 8 diagonals. As compared to regular hexagon (Also convex hexagon) it has one less number of diagonals. This is because one line joining two of its vertices (that are at the end of sides forming >180 angle) fall outside the hexagon.
Where does a convex lens make an image fall for a farsighted person A beyond the retina of the eye B before the retina of the eye C on the retina of the eye?
on the retina of the eye
Why does north east India get high rainfall?
north India gets high rain fall because of garokashi jayantia hill ,the shape of the hill is concave and when the wind comming from the equator collids with it it directly gos up and condences and there is a heavy rain fall
Why concave lens is the lens could correct the image formed of a nearsighted person?
Human eye is optical miracle.Depending on the distance of the object, we have to change the position of the screen.In case of human eye, screen (Retina) is kept at fixed distance and eye lens is elastic and it becomes more or less thin or thick, so as to adjust image on retina. This phenomena is called accommodation. In near sighted persons lens is more convex than it should be. So we put concave lens in front of eye, so that image of distant object should fall on retina. Human brain is also miracle and after few days, it starts guessing the actual distance of the object.
