Question

Find the power of a concave lens of focal length 2m ?​

Answer 1

Answer:

According to the sign convention, the focal length of a concave lens is always negative.Given parameter

Focal length of concave lens f = 2 m

Power of lens can be calculated using the formula

P= 1/f

P = 1/−2

P = – 0.5D

hope it helps you..

Answer 2

The given focal length of the concave lens is f = 2 m. It is negative because a concave lens always has a negative focal length. The unit of power is dioptre (D) and 1D = 1m-1.