Question

The relation between the focal length f and the radius of curvature R of a spherical mirror is:

विकल्प

• \[f = 2R\]

• \[f = R\]

• \[f = \frac{R}{2}\]

• \[f = \frac{R}{4}\]

Answer 1

The principal focus of a spherical mirror lies midway between the pole and the centre of curvature, so the focal length is half the radius of curvature: \[f = \frac{R}{2}\].