Question

What is the shape of the wavefront in each of the following cases:

1. Light diverging from a point source.

2. Light emerging out of a convex lens when a point source is placed at its focus.

3. The portion of the wavefront of light from a distant star intercepted by the earth.

Answer 1

1. It is spherical wavefront,

2. It is plane wavefront.

3. Plane wavefront (a small area on the surface of a large sphere is nearly planar).