Question

The distance between the pole and the center of curvature of a spherical mirror, in terms of its focal length f, is equal to:

• A. f
• B. 2f
• C. f/2
• D. f/4

Answer 1

Answer:

B. 2f

The distance between the pole and the center of curvature of a spherical mirror is twice the focal length, or 2f. Radius of curvature is observed to be equal to twice the focal length for spherical mirrors with small apertures. Hence R = 2f. We can say clearly that the principal focus of a spherical mirror lies at the centre between the centre of curvature and the pole.