Q. Two thin lenses whose powers are $+ 2D$ and $- 4D$ respectively combine, then the power of combination is
A) $- 2D$
B) $+ 2D$
C) $- 4D$
D) $+ 4D$
Explanation
(a) $P = P_{1} + P_{2} = 2D - 4D = - 2D$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.