Ampere, referred to security, is the International System of Units in the current strength of the unit, the symbol is A. at the same time it is also one of the seven basic units of the International System of Units . Ampere is the French mathematician and physicist Andre - Marie Ampere named, in honor of his contribution in terms of classical electromagnetism.

The actual situation, ampere is a unit of time cross-sectional measure the amount of charge through a conductor. Within one second by the cross section of 1 coulomb charge (6.241 × 1018 electrons in the charge), the current size of 1 amp

small current can be expressed in mA, microamps and other units.

1 Amp (A) = 1000 (mA)

1 milliamperes (mA) = 1000 microamps (μA)

Ampere force law of proof in a parallel existence of two straight power-attraction or repulsion between wires. This force is used to formally defined amps:

Vacuum, in two parallel infinitely long straight conductor cross-section can be ignored, and the distance of one meter. Through the same size, the same constant current direction in the two wires, when the wire is attractive per meter by 2 × 10-7 Newton, the two wires of the current of one ampere.

Ampere was originally defined as a centimeter - tenth - second current unit abampere - grams. Its size is so determined to ensure the international system of units derived from other units ampere value obtained is appropriate.

"International ampere" is an older unit of electric current, defined as the silver nitrate solution to precipitate the current 0.001118000 grams of silver per second. After a more accurate measure found that the current is 0.99985 A.

This unit Ampere and Watt balance and Ohm's law in the unit volts, ohms linked.