The dispersive powers of the materials of the two lenses are

Last updated: 6/28/2023

The dispersive powers of the materials of the two lenses are in the ratio 4 3 If the achromatic combination of these two lenses in contact is a convex lens of focal length 60 cm then the focal lengths of the component lenses are 1 20 cm and 25 cm 3 15 cm and 40 cm 2 20 cm and 25 cm 4 15 cm and 20 cm