Question

Distance btw F1 and F2 is 20 cms . Find the power of the convex lens​

Answer 1

Given,

Distance between the F1 and F2 of a convex lens is 20 centimetres.

For calculating the power of the given convex lens we have to first calculate the focal length of the convex lens. And,for an easy calculation,we are assuming that the given convex lens is a symmetrical convex lens.

So,

Focal length = (Distance between F1 and F2)/2 = 20/2 = 10 centimetres

Now,the power of the lens

= 1/ focal length of the lens

= 1/10

= 0.1 D

Hence,the power of the given convex lens is 0.1 D