Question

define 1dioptre of power of lens
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Answer 1

A dioptre (British spelling) or diopter (American spelling) is a unit of measurement of the optical power of a lens or curved mirror, which is equal to the reciprocal of the focal length measured in metres. (1 dioptre = 1 m−1.) It is thus a unit of reciprocal length.

Answer 2

Answer:

1 Dioptre is the power of a lens whose focal length is 1metre

Explanation:

I highlighted 1metre because you should be careful while doing calculations.

Always convert focal length  to  metre

The relation between power and focal length of a lens is

p=1/f

OR

f=1/p

thats all