find (a) the foocal length of the other and also (b) the distance between the  lenses.
Channel: Doubtnut
Date: 2021-11-02

It is required to from a converging achromatic system of length 30m consistng of two lenses made of the the same matrial. If one lenses be convex and of focal length 0.20m, find (a) the foocal length of the other and also (b) the distance between the  lenses.