Question

what is Dioptre?....​

Answer 1

Answer:

1. A dioptre or diopter is a unit of measurement of the optical power of a lens or curved mirror.

2. Which is equal to the reciprocal of the focal length measured in meters.

3. It is thus a unit of reciprocal length.

4. For example, a 3-dioptre lens brings parallel rays of light to focus at 1⁄3 meter.

Answer 2

Dioptre:

• For measurement of the optical power of a curved mirror, the unit that uses is called a dioptre.
• Optical power is equal to the reciprocal of the focal length.
• Optical power is measured in metres.
• The dioptre is based on the SI-metric system.
• The SI unit of power of lens is dioptre whose focal length is one meter, which is denoted by the letter D.
• 1 dioptre (D) = $p=\frac{1}{f}$

         Where $f$ = focal length