Question

Find the focal length of a lens of the power 2.0 D.what type of lens in this

Answer 1

1/f = 2D

f= 1/2=0.5m

it is a concave lens

Answer 2

Explanation:

Power of lens, P= 1/f

P= -2D

f= -1/2 = -0.5 m

A concave lens has a negative focal length. Hence, it is a concave lens.