A convex lens has a focal length of 10cm. What is the power of the lens?

Answer:

Convex lens have the ability to converge a parallel beam of light into a point. This point is called the focal point of the convex lens and the distance from the optical centre to the focal point is called the focal length.

Focal length (f) = 10cm = 0.1m

∴ p = 1 / f

p = 1 / 0.1

p = 10 D.