Question

if the power of the lens is -2D what is the focal lenght

Answer 1

Answer:

The power of a lens is defined as the reciprocal of its focal length in metres, or P=f1, where P is the power in diopters and f is the focal length in metres.

Explanation:

Power of lens (P) =

f

1

Here, focal length, f=−2m

Therefore, P=

−2

1

i.e., Power of the lens, P=−0.5 dioptre

The diopter is the unit of measure for the refractive power of a lens. The power of a lens is defined as the reciprocal of its focal length in metres, or P=

f

1

, where P is the power in diopters and f is the focal length in metres.

Answer 2

Hey Pal_

Answer :

Given: power of lens, P = -2 D = -2 $m^{-1}$

Focal length, F = $\frac{1}{P}$

F = $\frac{1}{-2}$

F = -0.5 m

The Given lens is Concave