Question

Calculate the power of concave lens of focal length 5 m

Answer 1

Answer:

Power is defined as the reciprocal of focal length.

Therefore, power, P=f(in metres)1​

Given: f=−10m

P=−5/1​⇒P=−0.5D

Step-by-step explanation:

Answer 2

Answer:

If the focal length of a concave lens is 5m, then its power is -0.2 Dioptre

Step-by-step explanation:

Given

The focal length = 5m

For a concave lens, the focal length is negative

So,

The focal length = -5m

Power = 1/ focal length

So power = 1/-5 = -1/5 = -0.2 Dioptre

So the power of the concave lens is -0.2 Dioptre