Question

Draw a diagram to show the refraction of a plane wave front incident on a convex lens and hence draw the refracted wavefront.

Answer 1

Hint: As we know that convex lens is thicker at the middle and behaviour of the convex lens is converging. When a plane wave front falls on the convex lens then the light will refract towards the focal plane.

Complete step by step answer:
As we know wave front wave front is a surface in the path of wave motion on which the disturbances at every point have the same phase. On the basis of source of light, wave front is of three types-
-Spherical wave front
-Cylindrical wave front
-Plane wave front

When the light ray is incident parallel to the principal axis then it is refracted towards the principal axis. Similarly when the plane wave front is incident on the convex lens it refracts towards the focal plane. As light is focused on a point, it is converging and the emerging wave front will be spherical converging.

Note: A plane wave front is a set of waves travelling in a plane. It is seen when light comes from an infinite source.
-A cylindrical wave front comes with a horizontal slit.
-A spherical wave front comes from a point source nearby.
-Additionally, a convex lens is a converging lens. It will converge the rays of light that travel parallel to its principal axis