Question

A convex lens of focal length 10 cm forms a real image of the same size as the object. The distance between the object and its image will be:

• A. 10 cm
• B. 20 cm
• C. 30 cm
• D. 40 cm

Hint:

For a convex lens forming a real image of the same size as the object, the distance between the object and the image is twice the focal length.

Answer 1

The Correct Option is B

For a convex lens forming a real image of the same size as the object, the object and image must be placed at equal distances from the focal point. Thus, the object distance ($u$) and image distance ($v$) will be equal in magnitude but opposite in direction, and the total distance between the object and the image will be twice the focal length. Therefore, the distance between the object and its image is 20 cm.