In the Physical, the inductance will be that property exhibited by electrical circuits by which an electromotive force is produced once there is a variation in the current that passes, either through the circuit itself or through another one close to it.
The concept of inductance was popularized by the English physicist, electrical engineer, mathematician and radio operator Oliver Heaviside on February 1886, meanwhile, the symbol with which it is distinguished, the letter L capital letter, has been imposed in homage to German physicist Heinrich Lenz, who also, like Heaviside, made important contributions to the discovery of this property.
And on the other hand, the term is used to refer to the circuit or circuit element that has inductance.
In an inductor or in a coil, inductance will be called the relationship that will be established between the magnetic flux and the intensity of the electric current. Since it is quite complex to measure the flux that embraces a conductor, instead the variations of the flux can be measured only through the voltage that is induced in the conductor in question by the variation of the flux. In this way we will obtain quantities that are plausible to be measured, such as current, voltage and time.
Meanwhile, the inductance will always be positive, except in those electronic circuits specially designed to simulate negative inductances.
As stated in the International System of Measurements, if the flow is expressed in weber (unit of magnetic flux) and intensity in amp (unit of electrical intensity), the value of the inductance will be in Henry, symbolized with the letter H capital letter and that in the aforementioned system is the unit attributed to electrical inductance.
Practical inductance values range from a few tenths of H for a one millimeter long conductor to several tens of thousands of H for coils made with thousands of turns around ferro-magnetic cores.
