## Why isn't CHARGE a fundamental quantity rather than CURRENT?

Almost all physics or engineering textbooks have a table of the SI units
that are based on six fundamental quantities. The one that is listed for
the quanity "electric current" is always "ampere". However, usually a few
pages past this fundamental table lies a definition of the ampere. 1 ampere
= 1 coulomb/second. This makes it sound more like a derived unit than a
fundamental unit. It seems more likely that the fundamental quantity
"electric current" should be replaced by the quantity "charge" and that the
fundamental unit should be the coulomb. While amperes can be broken down
into coulombs and seconds, the coulomb cannot be broken down (except to a
specific count of electrons or protons). Why does there seem to be some
contradiction between the definition of a fundamental quantity (a quantity
that can't be described in terms of another quantity) and the definition of
electric current? Why isn't charge along with the coulomb included in the
fundamental quantities table?
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 Quote by tan99 Almost all physics or engineering textbooks have a table of the SI units that are based on six fundamental quantities. The one that is listed for the quanity "electric current" is always "ampere". However, usually a few pages past this fundamental table lies a definition of the ampere. 1 ampere = 1 coulomb/second. This makes it sound more like a derived unit than a fundamental unit. It seems more likely that the fundamental quantity "electric current" should be replaced by the quantity "charge" and that the fundamental unit should be the coulomb. While amperes can be broken down into coulombs and seconds, the coulomb cannot be broken down (except to a specific count of electrons or protons). Why does there seem to be some contradiction between the definition of a fundamental quantity (a quantity that can't be described in terms of another quantity) and the definition of electric current? Why isn't charge along with the coulomb included in the fundamental quantities table?
It's true that 1 amp=1 Coulomb/second but of course 1 Coulomb=1 Amp second.I think the choice of what's considered to be more fundamental is guided largely by the experimental ease by which the unit can be established.The Ampere is defined with reference to the force between parallel current carrying wires which presents experimental difficulties to establish exactly but nevertheless is measurable to a high degree of accuracy.If we don't define the Coulomb with reference to the Ampere then how else should we define it?There must be ways but I'm assuming that the experiments needed to establish the unit are less accurate than the ones currently used.Anyway,like yourself I feel that the Coulomb is more fundamental than the Ampere.
 Recognitions: Science Advisor I wouldn't read very much into the fact that Amperes are an SI base unit, rather than Coulombs. Heck, moles are an SI base unit, and it's not even a measure of anything.

 Tags charge, current, fundamentals, si units, standard

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