Question

A point source is placed at the focus of a convex lens. After refraction, on the other side of the lens we will get

• A. a cylindrical wavefront
• B. a spherical wavefront
• C. a circular wavefront
• D. a plane wavefront

Answer 1

The correct option is D a plane wavefront

When a point source of light is placed at the focus of a convex lens, it produces parallel rays of light after refraction. Parallel rays of light constitute a plane wavefront. This is illustrated in the diagram given below.




Hence, $\left(D\right)$ is the correct answer.