Question

A plane wave front falls on a convex lens. The emergent wave front:

• A. converges to a point
• B. diverges from a point
• C. does not suffer any refraction
• D. may or may not converge at point

Answer 1

The correct option is A converges to a point

Although a convex lens is s converging lens, it does not ensure that all emerging wave front would be converging. It depends upon the incident wave front. It only has a converging tendency. There may be cases when a diverging wave front is not converged enough, and the emergent wave front is still diverging.

However a plane wave front would always be converged by a convex lens.