Q
A convex lens of power 5 D is in contact with a concave lens of power -3 D. What is the combination's focal length?
RRB Group-D
22/08/2022 / Shift-II
2022
✓ Answer:
A
50 cm
P = 5 - 3 = 2 D, so f = 1/2 m = 50 cm.