Question

If power of a lens is +2.0 D.
What will be its focal length.
Please answer me fast.

Answer 1

We know that power is inversely proportional to focal length.
Therefore...2D=1/f
f=1/2=0.5m.

Answer 2

p=1/f
power=1/2=0.5
as by the formula power is the inverse of focal length