Question

the focal length of a lens of power -2.5 dioptre is​

Answer 1

Answer:

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• Power = -2. 5 D
• Focal length = $\frac{1}{P}$

◗ 　Focal length = $\frac{1}{-2.5}$

◗ 　Focal length = $\frac{1}{-0.4}$ cm

The focal length is negative so, the lens is a Concave lens.

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