Q

What is the relation between focal length f and radius of curvature R?

RRB Group-D 22/09/2022 / Shift-II; 23/08/2022 / Shift-II; 17/08/2022 / Shift-II; 22/10/2018 / Shift-II 2022; 2018
✓ Answer: C R = 2f
For a spherical mirror in the paraxial approximation, R = 2f.