A lens has a focal length of, -10 cm. What is the power of the lens and what is its nature?

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Solution

As focal length is negative, the lens is diverging in nature, i.e., it is a concave lens.

Focal length, $f = - 10 c m = - 0.1 m$

Power $= \frac{1}{f} = \frac{1}{- 0.1} = - 10 D$

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A lens has a focal length of, -10 cm. What is the power of the lens and what is its nature?

As focal length is negative, the lens is diverging in nature, i.e., it is a concave lens. Focal length, f=−10 cm=−0.1 m Power =1f=1−0.1=−10 D

As focal length is negative, the lens is diverging in nature, i.e., it is a concave lens.

Focal length, $f = - 10 c m = - 0.1 m$

Power $= \frac{1}{f} = \frac{1}{- 0.1} = - 10 D$