Physics and Chemistry

Electricity and Magnetism

How did the electrical term ampere originate?

It was named for André Marie Ampère (1775–1836), the physicist who formulated the basic laws of the science of electrodynamics. The ampere (A), often abbreviated as “amp,” is the unit of electric current, defined at the constant current, that, maintained in two straight parallel infinite conductors placed one meter apart in a vacuum, would produce a force between the conductors of 2 × 10–7 newton per meter. For example, the amount of current flowing through a 100-watt light bulb is 1 amp; through a toaster, 10 amps; a TV set, 3 amps; a car battery, 50 amps (while cranking). A newton (N) is defined as a unit of force needed to accelerate one kilogram by one meter second–2, or 1 N = 1 (Kg x M)/s–2.


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