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
Martin Ohm 1852; and he also taught in the military school from 1826 to 1849. Ohm was the first to fully develop the theory of the exponential "a" when both "a" and "b" are complex numbers in 1823. He is also often credited with introducing the name "golden section" ("goldener Schnitt"). Ohm's students included Friedrich August, Friedrich Bachmann, Elwin Bruno Christoffel, Paul Bachmann, Joseph Brutkowski, Heinrich Eduard Heine, Rudolf Lipschitz, Leo Pochhammer, Friedrich Prym, Wilhelm Wagner, Hermann Waldaestel, Wilhelm Wernicke, Elena Gerz, Valentien Gerz, and Johanna Gerz. Martin Ohm Martin Ohm (May 6, 1792, Erlangen – April 1, 1872, Berlin) was a