Question

A concex lens lens of focal length 40 cm os in contact woth a concave lens of focal length 25 cm the power of the combination is

Answer 1

SOLUTION

Convex lens

f= 40cm

P= 100/f = 100/40 = 2.5D.

Concave lens

f= 25cm

P= 100/f = 100/25 = -4D

As, we know that total power is equal to the algebraic sum.

Power of combination

=) 2.5D + (-4D) = -1.5D

hope it helps ☺️