3 A convex lens A of focal length 20 cm and a concave lens B

Last updated: 6/11/2023

3 A convex lens A of focal length 20 cm and a concave lens B of focal length 5 cm are kept along the same axis with a distance d between them If a parallel beam of light falling on A leaves B as a parallel beam then the distance d in cm will be 1 2 3 4 50 30 15