The power of a lens is -2.0 D. Here 'D' stands for:

Options

A. distance
B. distance
C. dioptre
D. degree

Answer

C

Explanation

A dioptre 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 `=1m^(-1))` . It is thus a unit of reciprocal length.