Radius OF curvature

A biconvex lens with both faces of the same radius of curvature is to be manufactured from a glass of refractive index 1.55. What should be the radius of curvature for the focal length of the lens to be 20 cm ?

What is the relation between the focal length and radius of curvature of a spherical mirror (concave mirror or convex mirror ) ? Calculate the focal length of a sphrical mirror whose radius of curvature is 25 cm.

A thin plano-convex lens acts like a concave mirror of radius of curvature 20 cm when its plane surface is silvered. The radius of curvature of the curved surface if index of refraction of its matarial is 1.5 will be

A charged particle moves in a uniform magnetic field perpendicular to it, with a radius of curvature 4 cm. On passing through a metallic sheet it loses half of its kinetic energy. Then, the radius of curvature of the particle is

Double convex lenses are to be manufactured from a glass of refractive index 1.55, with both faces of the same radius of curvature. What is the radius of curvature required if the focal length of the lens is to be 20 cm?

A double convex lens of focal length 6 cm is made of glass of refractive index 1.5. The radius of curvature of one surface is double that of the other surface. The value of smaller radius of curvature is