Q10.2 What is the shape of the wavefront in each of the following cases:
(b) Light emerging out of a convex lens when a point source is placed at its focus.
The shape of light emerging out of a convex lens when a point source is placed at its focus is Parallel .when light rays come from infinity parallelly, they intersect at focus of convex lens and hence when light is emerging from the focus, the rays will get parallel to each other after coming out of the convex lens, because path of light rays are reversible.