Question

A concave lens of focal length 25cm will have its power

Answer 1

Hey There!

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We know that The power of lens is the reciprocal of its Focal length in Meter .

SI unit - Diopter

So Your answer would be 1/ 0.25 diopter
i.e. 4 diopters.

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Hope this helps mate!

Answer 2

Hence its a concave lens than than the
Power = 1 / focal length
Now we put the values
Power = 1/ 25
=0.4 Dioptre