Question

Himanshu has two lenses A and B. When he touches both the lenses he finds that A is thicker at the centre than the edges and B is thinner at the centre as compared to its edges. He has to focus sunlight on a particular point. Which of the following statement is true?

• A. He should use lens A.
• B. Neither of the lenses can be used.
• C. Insufficient information
• D. He should use lens B.

Answer 1

The correct option is A He should use lens A.

Himanshu should use lens A. Such a lens which is the thickest at the middle and gradually becomes thinner towards its ends is called a convex lens. A convex lens converges a beam of parallel rays of light. Thus, it is also known as converging lens. A converging lens (like that used in a magnifying lens) is used to focus sunlight on a particular point.