Question

Convex lens of f 40 cm is in contact with a concave lens of f 50 cm the focal focallength of combination

Answer 1

Answer:. -0.015

Explanation

P=1/f

power of combination of lens.

P1+P2+P3...

1/f1+1/f2+1/f3+....

Therefore,

P=1/40+(-1/25)

P=1/40-1/25

P=-0.015