Question

The relation between focal length and radius of curvature is given by ...

Answer 1

The focal length (f) of a lens is the distance between the center of the lens and the point at which the reflected light, of a beam of light travelling parallel to the center line, meets the center line (principal axis). The radius of curvature (r) is the radius of the lens that forms a complete sphere.

Answer 2

$\textbf{Answer is in Attachment !}$