THE AMPERE
 

The ampere, symbolized by the uppercase nonitalicized English letter A (or abbreviated as amp), is the unit of electric current. A flow of approximately 6.241506 × 10¹⁸ electrons per second past a given fixed point in an electrical conductor produces an electrical current of 1 A.
Various units smaller than the ampere are often employed to measure or define current. A milliampere (mA) is one-thousandth of an ampere, or a flow of 6.241506 × 10¹⁵ electrons per second past a given fixed point. A microampere (μA) is one-millionth or 10^-6 of an ampere, or a flow of 6.241506 × 10¹² electrons per second. A nanoampere (nA) is 10^-9 of an ampere; it is the smallest unit of electric current you are likely to hear about or use. It represents a flow of 6.241506 × 10⁹ electrons per second past a given fixed point.
The formal definition of the ampere is highly theoretical: 1 A is the amount of constant charge-carrier flow through two straight, parallel, infinitely thin, perfectly conducting media placed 1 m apart in a vacuum that results in a force between the conductors of 2 × 10^-7 newton per linear meter. There are two problems with this definition. First, we haven’t defined the term newton yet; second, this definition asks you to imagine some theoretically ideal objects that cannot exist in the real world. Nevertheless, there you have it: the physicist venturing into the mathematician’s back yard again. It has been said that mathematicians and physicists can’t live with each other and they can’t live without each other.

مواضيع ذات صلة

THE TESLA

THE WEBER

THE HENRY

THE FARAD

THE HERTZ

THE SIEMENS

THE OHM

THE VOLT

THE COULOMB

THE WATT

THE JOULE

THE NEWTON