A biconvex lens has focal length `(2)/(3)` times the radius of curvature of either surface. Calculate refraction index f material of the lens.

A binovex lens has a focal lenth 2//3 tiems the radius of curvature of either surface.Calculate the refractive index of lens material.

A biconvex lens has a focal length half the radius of curvature of either surface. What is the refractive index of lens material ?

The focal length of an eqniconvex lens is equal to the radius of curvature of either face. What is the value of refractive index of the material same of the lens?