Question

How will the magnitude of magnification change, if an object placed at the center of curvature of a concave mirror is moved towards the focus?

• A. decreases
• B. increases
• C. remains constant
• D. magnification reaches infinity

Answer 1

The correct option is B

increases

Magnification is given by:
$\text{Magnification}=\frac{\text{Height of image}}{\text{Height of object}}$

At center of curvature,
Image size equals the object size. Magnitude of magnification is unity.

At focus,
Image size equals infinity. Magnitude of magnification is infinity.

Therefore, it can be concluded that the magnification is increasing.