Question

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

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

Answer 1

The correct option is B

He should use lens A

Himanshu should use lens A. Such a lens which is thicker at the middle and is thinner towards the ends is called a convex lens. Convex lens converges a beam of parallel rays of light to a particular point after refraction through it.