Find the focal length of a lens of power – 2.0 D. What type of lens is this?

Q. 16 :- Find the focal length of a lens of power – 2.0 D. What type of lens is this? 

 

Answer:-

 

1
P =
f
1
– 2.0 =
f
−1
f =
m
2
− 1
f =
× 100 cm
2
f = − 50 cm = – 0.50 cm

The lens is a concave lens