Imperial and US customary measurement systems (42 US gallons, 34.97 imperial gallons or 159.0 litres) used in the oil industry has the dimension of volume and could be replaced by the gallon, cubic metre or litre. The definitions of potential difference (volt), electric current (ampere), electrical resistance (ohm) were defined in terms of metric units, international agreement having been reached at a series of IEC Congress in Chicago between 1881 and 1906 when the electrical industry was in its infancy. At that time the metric system had become established in continental Europe while in the United Kingdom metrication was an active issue. Similarly, the units of
Coefficients of potential Coefficients of potential In electrostatics, the coefficients of potential determine the relationship between the charge and electrostatic potential (electrical potential), which is purely geometric: where "Q" is the surface charge on conductor "i". The coefficients of potential are the coefficients "p". φ should be correctly read as the potential on the i-th conductor, and hence "formula_2" is the p due to charge 1 on conductor 2. or more formally Note that: The physical content of the symmetry is as follows: In general, the coefficients is used when describing system of conductors, such as in the capacitor. Given the electrical potential