Lower half of a convex lens is made opaque. Which of the following statement describes the image of the object placed in front of the lens?
(A) No change in image
(B) Image will show only half of the object
(C) Intensity of image gets reduced
Choose the correct answer from the options given below.
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (C) only
Every point of the object sends rays to every part of the lens, and all the rays from one object point that pass through the lens meet at the same image point. Covering half the lens removes half of these rays from each object point but leaves the other half to form the image.
(A) No change in image — Incorrect. The position and size of the image do not change, but fewer rays reach it, so it is not unchanged.
(B) Image will show only half of the object — Incorrect. The uncovered upper half still receives rays from every point of the object, so the complete image is formed.
(C) Intensity of image gets reduced — Correct. Only half the light passes through the lens, so the image is less bright (its intensity is roughly halved).