Question

What type of wavefront will emerge from the point source?

Answer 1

A wavefront is called the locus of all the points which vibrate or oscillate in the same phase. A wavefront can emerge from any kind of source, and for different kinds of sources the emerging wavefront can take different shapes.

Complete step-by-step solution:
Let us consider a point source (O). Let us assume that the point source is located in a homogeneous medium and it starts to vibrate. The energy coming out from this particle travels in every direction with a constant speed and equal distances are covered by it.
This locus of all points which vibrate or oscillate with the same phase, and it is called a wavefront.
The wavefronts emerging can be different for different kind of sources:
And for a point source , the wavefront emerging is spherical.

Additional Information:
Optical effects that depend on the wave nature of light are categorized as wave optics.
Huygen proposed 2 principles of wave:
Each point on a wavefront is a source of secondary disturbance.
Each wavelet emanating from this source of secondary disturbance spreads out in all directions with the speed of the wavefront. And the collection of all these wavelets give the shape of a new wave front.

Note: For point source, wave front is spherical
For a linear source, the wavefront is cylindrical
For a plane source, the wavefront is planar.
A very small portion of a large spherical wavefront can be approximately assumed to be treated as a plane wavefront .