Question

The power of lens used in a reading glass of a person is 1 dioptre.what is the nature of the lens ?

Answer 1

If the power of the lens is +1 D

The focal length would be 1 m or 100 cm

By the formula P = 1/f

So the nature of the lens is Convex as Convex lens has positive focal length

Similarly, if the power would be -1 D the focal length will also be negative and hence the nature of the lens would be Concave