Question

A convergent lens of power 5D is combined with a divergent lens of power -4D.

Then find the focal length and power of combination of both lenses.​

Answer 1

Explanation:

for converging lens , P= 1/f

5= 1/f

f= 1/5

for diverging lens , P=1/f

-4= 1/f

f= 1/-4

therefore 1/5 + 1/-4

-0.05