Question

a boy uses lens of focal length is 50cm .find the nature and power of lens​

Answer 1

focal length +50 of a lens tells that it is convex lens as its focal length is in plus......its power ,p=1/f (focal length)

p=1/+50

=+0.02  dioptres......

Answer 2

focal length +50 of a lens tells that it is convex lens as its focal length is in plus......its power ,p=1/f(focal length)

p=1/+50

=+0.02 dioptres.....

Hope it will help u