# Can a lens be convex and concave?

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A lens is a shaped piece of transparent glass or plastic that refracts light. … A lens can be convex or concave .

## Can a lens be both concave and convex?

Telephoto Lenses Are Combinations of Convex and Concave Lenses. Most optical devices make use of not just one lens, but of a combination of convex and concave lenses. For example, combining a single convex lens with a single concave lens enables distant objects to be seen in more detail.

## Are lenses concave or convex?

Most lenses are spherical lenses: their two surfaces are parts of the surfaces of spheres. Each surface can be convex (bulging outwards from the lens), concave (depressed into the lens), or planar (flat). The line joining the centres of the spheres making up the lens surfaces is called the axis of the lens.

## What happens when you combine a convex and concave lens?

When you put lenses together, their power actually adds. The power is the inverse of the focal length. … Now, you have the concave lens next to the convex lens. Since you said a real image is formed, that means the absolute value of the power of the concave lens in smaller than the power of the convex lens.

## How do you differentiate between convex and concave lens?

A convex lens is thicker at the centre and thinner at the edges. A concave lens is thicker at the edges and thinner at the centre. Due to the converging rays, it is called a converging lens.

## How can you identify a concave and convex lens without touching it?

Answer: If the curved surface is bulging outwards then it’s convex lens and if the curved surface is curved inwards then it’s concave lens.

## Is a convex lens?

A convex lens is also known as a converging lens. A converging lens is a lens that converges rays of light that are traveling parallel to its principal axis. They can be identified by their shape which is relatively thick across the middle and thin at the upper and lower edges.

## What are concave lenses?

A concave lens is a lens that possesses at least one surface that curves inwards. … It is a diverging lens, meaning that it spreads out light rays that have been refracted through it. A concave lens is thinner at its centre than at its edges, and is used to correct short-sightedness (myopia).

## Where are convex lenses used?

Convex lenses are used in microscopes, magnifying glasses and eyeglasses. They are also used in the cameras to create real images of objects present at a distance.

## Why are concave mirror and convex lens considered both converging while convex mirror and concave lens are diverging?

Light reflects from a mirror. … A concave mirror converges light to a focal point. For lenses, light converges to a point for a convex lens. A convex mirror diverges light, as does a concave lens.

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## What is the power of combination of convex lens and concave lens of the same focal length?

Hint: When a concave lens and a convex lens of the same focal length are in contact, then the power of the lens combination will be zero and its focal length will be infinite. Therefore, the combination behaves as a plane glass plate.

## What are the two devices that use combination of concave and convex lens?

Answer: Telephoto Lenses Are Combinations of Convex and Concave Lenses.

## What is the difference between convex and Biconvex lens?

As their name implies, both plano-convex and biconvex lenses have either one or two surfaces with positive spherical contours. … In the case of a plano-convex design, one surface remains flat while the second has a positive curve and for biconvex lenses, both surfaces are positively curved.