Question

Spherical lenses have two radii of curvature as they have two refracting surfaces.

• A. True
• B. False

Answer 1

The correct option is A True

A general spherical lens is shown in the figure below. It has two refracting curved surfaces.

These two curved surfaces are the parts of two spheres, hence the lens has two radii of curvature.

Note that all types of spherical lenses have two radii of curvature as they have two spherical curved surfaces. For plano convex lens we can assume the plane surface as a part of a very big sphere.