Akhil told Avinash that convex lens converts the three types of rays i.e., parallel, divergent, convergent rays to convergent rays. Avinash does not agree with Akhil's words. Support your argument with ray diagrams.

In which terms, the degree of convergence or divergence of light ray that can be achieved by a lens is expressed ?

Some rays falling on a converging lens are focussed 20 cm from the lens. When a diverging lens is placed in contact with the converging lens, the rays are focussed 30 cm from the combination. What is the focal length of the diverging lens?

{:(" Column - I "," Column - II "),(" a) ""A lens that can form a real image"," P) ""Convex lens"),(" b) ""A lens that forms virtual and diminished image "," Q) ""Concave lens"),(" c) ""Incident ray is parallel to emergent ray"," R) ""Denser medium"),(" d) ""A substance in which speed of light is less"," S) ""Rectangular glass lab"):}