Question

State whether true or false:
A concave lens is used as a magnifying glass
A. True
B. False

Answer 1

Hint:We are asked to check whether the given statement is true or false. First you need to know what a magnifying glass does and what a concave lens is. Then with a diagram check what type of image is formed by a concave lens and whether it satisfies the condition for magnifying glass.

Complete answer:
Given the statement, a concave lens is used as a magnifying glass.To know whether the statement is true or false, first let us know about concave lens and magnifying glass.Magnifying glass is used to magnify or enlarge an image of an object.Concave lens is a lens which has its surfaces inwards. Let us understand with diagram

We can observe that in a concave lens, the light beam coming from the source diverges, so the image formed will be virtual and diminished. Therefore, a concave lens cannot be used as magnifying glass.

The answer of the question will be option B.

Note: The lens used for magnifying glass is convex lens. Convex lenses are lenses with surfaces outwards and are also known as converging lenses that is the light beam after passing through convex lens converges at a point and forms a real image. For convex lenses to be used as simple magnifying glass, the object should be placed at a distance less than the focal length of the lens. The important point to be remembered is that a convex lens is a converging lens and a concave lens is a diverging lens.