Question

Find the power of a concave lens of focal length - 15

Answer 1

Answer:

The power of the lens, P=

f

1

Focal length of concave lens, f=−15m

P= -15

Then the 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 dioptres and f is the focal length in metres.