Question

What is the power of lens? The focal length of convex lens is 20 cm what is its

power?​

Answer 1

Answer:

Power of a lens is defined as the inverse of focal length (in meters) of the lens. It is a measure of the amount of deviation of light ray produced by a lens, more the power, more is the deviation. Unit of power is Dioptre (D). P=f1.

20 CM in metres= 20/100m=1/5 metres. power of a lens= 1/1/1/5=5 dioptres.

Answer 2

Answer:

The reciprocal of focal length is called power of lens...

P=100/f

100/20=5Diopters