Question

Assertion (A): If the focal length of a converging mirror is 15 cm, then its radius of curvature will be 7.5 cm.

Reason (R): In order to use a converging mirror of focal length 15 cm as a make-up mirror, the face should be at a distance less than 15 cm from the converging mirror.

पर्याय

• Both A and R are true and R is correct explanation of the assertion.

• Both A and R are true but R is not the correct explanation of the assertion.

• A is true but R is false.

• A is false but R is true.

Answer 1

A is false but R is true.

Explanation:

Assertion (A) is false because the radius of curvature (R) is twice the focal length (R = 2f), meaning a converging mirror with a 15 cm focal length has a radius of curvature of 30 cm, not 7.5 cm. Reason (R) is true because a converging (concave) mirror only forms an upright, magnified, and virtual image, which is required for a make-up mirror when the object is placed within its focal length (at a distance less than 15 cm).