Q17. Light emerges out of a convex lens when a source of light kept at its focus. The shape of wavefront of the light is : (1) both spherical and cylindrical (2) plane (3) spherical (4) cylindrical
Q17. Light emerges out of a convex lens when a source of light kept at its focus. The shape of wavefront of the light is :\\
(1) both spherical and cylindrical\\
(2) plane\\
(3) spherical\\
(4) cylindrical