Abampere

The abampere (abA), also called the biot (Bi) after Jean-Baptiste Biot, is the basic electromagnetic unit of electric current in the emu-cgs system of units (electromagnetic cgs). One abampere is equal to ten amperes in the SI system of units. An abampere of current in a circular path of one centimeter radius produces a magnetic field of 2 π oersteds at the center of the circle.

The emu-cgs (or "electromagnetic cgs") units are one of several systems of electromagnetic units within the centimetre gram second system of units; others include esu-cgs, Gaussian units, and Lorentz–Heaviside units. In these other systems, the abampere is not one of the units; the "statcoulomb per second" or statampere is used instead.

The other units in this system related to the abampere are:

• abcoulomb – the charge that passes in one second through any cross section of a conductor carrying a steady current of one abampere
• abhenry – the self-inductance of a circuit or the mutual inductance of two circuits in which the variation of current at the rate of one abampere per second results in an induced electromotive force of one abvolt
• abohm – the resistance of a conductor that, with a constant current of one abampere through it, maintains between its terminals a potential difference of one abvolt