Question

Define a wavefront. Using 'Huygens' principle, draw the shape of a refracted wavefront, when a plane wave is incident on a convex lens.

Answer 1

The locus of points, which oscillate in phase is called a wavefront; thus a wavefront is defined as a surface of constant phase.

In the given figure we consider a plane wave incident on a thin convex lens, the emerging wavefront is spherical and converges to point F which is known as the focus.