If a concave and convex lens of equal focus are kept in contact what is the effective focal length?
1 Answer
Feb 12, 2016
Effective focal length in
Explanation:
When two lenses are kept in contact, powers of the lenses are simply added.
Power of a lens is positive for convex lens and negative for concave lens.
Numerically power of a lens is given by
As numerically, focal length is same but opposite in size, combined power will be
