si unit of power of a lens is dioptre.
si unit of power of a lens is?
dioptre
optical power





























optical power (also referred to as dioptric power, refractive power, focusing power, or convergence power) is the degree to which a lens, mirror, or other optical system converges or diverges light. it is equal to the reciprocal of the focal length of the device: . high optical power corresponds to short focal length. the si unit for optical power is the inverse metre (m), which is commonly called the dioptre.





























converging lenses have positive optical power, while diverging lenses have negative power. when a lens is immersed in a refractive medium, its optical power and focal length change.
optical power
the gas constant occurs in the ideal gas law, as follows:





























where "p" is the absolute pressure (si unit pascals), "v" is the volume of gas (si unit cubic metres), "n" is the amount of gas (si unit moles), "m" is the mass (si unit kilograms) contained in "v", and "t" is the thermodynamic temperature (si unit kelvins). "r" is the molar-weight-specific gas constant, discussed below. the gas constant is expressed in the same physical units as molar entropy and molar heat capacity.





























section::::dimensions.





























from the ideal gas law "pv" = "nrt" we get:
gas constant