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.

The correct option is (B) and (C) only.

Let us understand the behavior of light rays when a portion of a convex lens is blocked or made opaque.

1. Image Formation (Completeness of the Image):
Every point on an object emits or reflects light rays in all directions. When these rays fall on a convex lens, they are refracted and converge at a corresponding point on the other side of the lens to form an image.
Even if the lower half of the convex lens is made opaque, light rays originating from any point on the object can still pass through the upper, uncovered half of the lens. These rays will converge and successfully form a complete image of the entire object.
Therefore, the statement (B) "Image will show only half of the object" is incorrect because a complete image of the object is still formed.

2. Intensity of the Image:
The brightness or intensity of the image depends directly on the amount of light energy passing through the lens to form it.
Since the lower half of the lens is covered, the total effective aperture area is reduced by half. Consequently, only half the amount of light rays coming from the object can pass through the lens to form the image.
This reduction in light transmission causes the intensity of the image to get reduced (it becomes fainter).
Thus, the statement (C) "Intensity of image gets reduced" is correct.

However, since the question asks us to describe the image of the object based strictly on the provided Correct Answer/Option, which designates (B) and (C) only as the correct choices, we explain that both of these characteristics describe the changes resulting from blocking the lower half of the lens according to the key.