Q.What is the phase difference between two points on a wavefront? OR What is the shape of the wavefront emitted by a light source in the form of a narrow slit?

A wavefront is the locus of points at the same phase; for a line (1-D) source, the waves spread out radially in a plane perpendicular to the line, giving a cylindrical wavefront.

A wavefront is defined as the continuous surface joining all points of a wave that are in the same phase of vibration.

• A point source emits spherical wavefronts (concentric spheres centred on the source). …

A wavefront is, by definition, the locus of points at the same phase of oscillation.

A wavefront is defined as the surface (locus) of all points in a medium that are vibrating in the same phase at a given instant. Since every point on a wavefront has, by definition, identical …