A plano-convex lens (focal length `f_2`, refractive index`mu_(2)`, radius of curvature R) fits exactly into a plano-concave lens (focal length`f_(1)` refractive index `mu_1`, radius of curvature R). Their plane surfaces are parallel to each other. Then, the focal length of the combination will be :

A plano-convex lens has refractive index 1.6 and radius of curvature 60 cm. What is the focal length of the lens?

A plano-convex lens has refractive index 1.6 and radius of curvature 60 cm. What is the focal length of the lens?

A plano-convex lens is made of refractive index 1.6. The radius of curvature of the curved surface is 60 cm. The focal length of the lens is

A plano convex lens is made of glass of refractive index 1.5. The radius of curvature of its convex surface is R. Its focal length is

A plano convex lens is made of glass of refractive index 1.5. The radius of curvature of its convex surface is R. Its focal length is

Find the focal length of plano-convex lens of material having refractive index of 1.5. Radius of curvature of convex surface is 10 cm.

The adjacent figure shows a thin plano-convex lens of refractive index mu_1 and a thin plano-concave lens of refractive index mu_2 , both having same radius of curvature R of their curved surfaces. The thin lens of refractive index mu_3 has radius of curvature R of both its surfaces. This lens is so placed in between the plano-convex and plano-concave lenses that the plane surfaces are parallel to each other. The focal length of the combination is