Question

Rays from the sun converge at a point 25 cm behind a convex lens. The distance at which an object be placed in front of the lens to get a virtual image, is ______.

Options

• 20 cm

• 40 cm

• 50 cm

• More than 50 cm

Answer 1

Rays from the sun converge at a point 25 cm behind a convex lens. The distance at which an object be placed in front of the lens to get a virtual image, is 20 cm.

Explanation:

Parallel rays from the sun converge at the focus, so the focal length (f) = 25 cm for the convex lens.

To obtain a virtual image, the object must be placed within the focal length (i.e., distance < 25 cm).

Among the options, only 20 cm is less than 25 cm.

Hence, the correct answer is 20 cm.