Question

What can be the minimum distance between an object and its image formed by a concave mirror?
( $f$ is the focal length of the mirror)

• A. Zero
• B. $f$
• C. $2f$
• D. $\frac{f}{2}$

Answer 1

The correct option is A

Zero

When an object is placed at the centre of curvature of a concave mirror, the image is also formed at the centre of curvature of the mirror. Hence, the distance between the object and the image formed is zero which is the minimum distance between object and image formed by a concave mirror.