Ampere W/V. Current can be measured by a multimeter, a device that can measure electrical voltage, current, and resistance. The standard ampere is most accurately realized using a Kibble balance, but is in practice maintained via Ohm's law from the units of electromotive force and resistance, the volt and the ohm, since the latter two can be tied to physical phenomena that are relatively easy to reproduce, the Josephson junction and the quantum Hall effect, respectively. At present, techniques to establish the realization of an ampere have a relative uncertainty of approximately a few parts in 10, and involve realizations 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