Question

The wave front due to source point at a finite distance from a source is?

Answer 1

Firstly, it depends upon the distance of the point source and the point where you want to see the wavefront. If you are close to the point source from where the light is emerging then the wavefront is taken to be spherical, else if you are too far away, practically at infinite distance from the source, then it is taken to be the plane wavefront. It should be noted that plae wavefront is just a limiting case of the spherical wavefront at practically large distances.

Answer 2

A wavefront is defined as the locus of points enhanced by propagation or movement of positions of identical phases.

It includes propagation of a point in 1D, a curve in 2D or a surface in 3D.

For an electromagnetic wave, the wavefront is represented as a surface of identical phase, and conventional optics can be used to modify it.

Wave front due to a point source at a finite distance from the source is spherical.

So, the answer is spherical wavefront.