Why the units are volt amperes?

Answer 1

Because the ampere is the SI unit of measurement for electric current. It is defined in terms of the magnetic effect of an electric current -i.e. the force between two, parallel, current-carrying conductors, expressed in terms of newtons per metre length.

Answer 2

The units of power in AC reactive circuits are volt-amperes instead of watts because the voltage and current are not in phase with each other. Volt-amperes is a better indication of how much power a source such as a transformer is supplying, because watts will be less than volt-amperes due to power factor, but that energy still has to be supplied.

Answer 3

Current is charge per time, or coulomb per second. We simplify that as the ampere. This is accepted convention.

An amount of charge is the coulomb.

Energy per charge is joules per coulomb, also known as the volt.

Charge per second is current in coulombs per second, also known as the ampere.

Per Ohm's Law, a current of one ampere with a voltage on one volt requires a resistance of one ohm, also known as one joule-second per coulomb squared, but the term ohm is so more more convenient.

A current of one ampere across a voltage of one volt dissipates a power of one watts, also known as one joule per second.

Memorize this, and you are well on you way to understanding Electricity 101.

Answer 4

It is not derivable from other units. The ampere is defined in terms of a quantity of electrons flowing past a point per second. A quantity of electrons has no connection to any other unit, it requires a means of counting (or at least estimating) the number of electrons that moved.

Answer 5

Because the French Physicist Ampere did a lot of important research and published

a lot of new knowledge relating to electric current, so when it came time for the

scientific community to define and name new units, they immortalized his memory

by perpetuating his name as the unit of current. But of course, the whole thing was

just a twist of fate, as so many of life's developments are. Had the discoveries been

realized and published by one of his young lab assistants instead of by Professor

Ampere himself, we might be measuring electric current today with a Schwartzmeter,

a Winkelmeter, a Cohenmeter, a Chevaliermeter, etc. The mind boggles at the thought

of how close we came.

Answer 6

It is called Ampere. As to why, well, I guess there must be SOME standard for current.

Answer 7

Presumably the currently used definition was chosen because it can be reproduced with greater precision than alternate methods.