Question

if the focal length of a lens 2m .then what is its power​

Answer 1

Answer :

p = 1/f

= 1/2m

= 0.5diopter

p = 0.5diopter

Answer 2

The power of the lens (P) = − 0.5 dioptre

Explanation:

Given,

The focal length of concave lens, f = − 2 m

To find, the power of the lens (P) = ?

We know that,

The power of the lens (P) = $\dfrac{1}{f}$

∴ The power of the lens (P) = $\dfrac{1}{-2}$

= − 0.5 dioptre

The diopter is the unit of measure for the refractive power of a lens.

Thus, the power of the lens (P) is − 0.5 dioptre.