General Science

  • noun in the SI system, the basic unit of electric current equal to a current between two parallel conductors in a vacuum that produces a force equal to 2x10–7 newtons per metre


  • noun a unit of electric current equal to one volt flowing through an impedance of one ohm

Cars & Driving


  • noun the base SI unit of electrical current, defined as the current flowing through an impedance of one ohm which has a voltage of one volt across it.


  • The electromotive force required to move one volt of electricity across one ohm of resistance. A measure of electrical current.

Origin & History of “ampere”

this international term for a unit of electrical current derives from the name of André-Marie Ampère (1775–1836), the French physicist and mathematician. It was officially adopted by the Congrès Électrique in Paris in 1881. Ampère himself is best remembered for first making the distinction between electrical current and voltage, and for explaining magnetism in terms of electrical currents. The term ammeter ‘current-measuring device’ (19th c.) was based on ampere.