Why is charge a derived quantity

mc2_phy

Why is charge a derived quantity????

Khashishi

convention. Current was measured before charge.

AbsoluteZer0

There are seven base units from which all other units are derived.

-meter (length)
-kilogram (mass)
-second (time)
-ampere (electric current)
-kelvin (temperature)
-candela (luminous intensity)
-mole (concentration of substance)

Electric charge is measured in Coulombs, or Amperes seconds.

jtbell

In SI, current is a fundamental unit (ampere) and charge is a derived unit (coulomb = ampere · second) for practical reasons. It's easier to implement the standard for current precisely, by measuring the force between two current-carrying wires, than it would be to implement a standard for charge precisely, involving something like measuring the force between two charges, or counting electrons.

AlephZero

Ampere seconds, not amperes per second.

AbsoluteZer0

My apologies.
Edited and corrected.

mc2_phy

No prob. Thanks for that. Really cleared it up