Question

A converging lens is used to form an image on a screen. When the upper half of the lens is covered by an opaque screen, what happens to the image?

• A. Half of the image will disappear
• B. No part of the image will disappear
• C. The intensity of the image will increase
• D. The intensity of the image will decrease

Answer 1

The correct option is D

The intensity of the image will decrease

1. Image formation by lens occurs when rays pass the lens and meet at some point on the other side or appear to meet.
2. If we cover the upper half of the lens with an opaque screen, less number of rays will contribute to forming the image.
3. As a result, the intensity of the image will be low.

Hence option D is correct.