Question

Calculate the focal length of a lens, if its power is - 2-5 D.
OR​

Answer 1

Explanation:

ملک اور بیرون ملک نافذ کرنے والے ممالک کے لئے یہ استعمال کرنے کے لئے آزاد اور

Answer 2

Explanation:

we know that power P=2.5D

P=

f

1

f=

2.5

1

=0.4m=40cm

Since the focal length of lens is positive so it is a convex lens. It is a converging lens.