The SI unit of the power of a lens is:
Dioptre
The power of a lens is a measure of how strongly it converges or diverges light and is defined as the reciprocal of its focal length in metres: \(P = \dfrac{1}{f}\).
Its SI unit is the dioptre (D), which equals one reciprocal metre. Metre and centimetre are units of length or focal length, not power, and lumen is a unit of luminous flux, unrelated to lens power.
Important Questions from Optics
Which one of the following colours may be obtained by combining green and red colours?
Which of the following are the primary colours of light?
Directions: The following items consist of two statements, Statement I and Statement II. You are to examine these two statements carefully and select the answers to these items using the code given below:
Statement I: Diamond is very bright.
Statement II: Diamond has very low refractive index
A non-SI unit called 'nit' is the unit of which of the following photometric quantities used to measure a multitude of light intensity?
Which among the following is used as a reflector in search lights?
