Define the coulomb and the ampere..

[mahela007]

Could someone please tell me what the definition of a coulomb is? and also what's the definition of the ampere? All the resources on the internet go in circles. Some say that the ampere is the flow of current at the rate of 1 coulomb per second.

Others say that 1 coulomb is the charge per second in a wire which carries a current of 1 ampere..

These two definition are basically the same and they go in an endless circle... One wouldn't be able to define either one without the other..... So can someone please tell me the correct definition of the coulomb?

[timo]

As a matter of fact, the definition on Wikipedia does not have this circular dependency:

Quantitatively, the ampere is defined to be the constant current which will produce an attractive force of [math]2 \cdot 10^{–7}[/math] newton per metre of length between two straight, parallel conductors of infinite length and negligible circular cross section placed one metre apart in free space. The ampere [...'] is defined without reference to the quantity of electric charge.

[insane_alien]

the ampere "is now defined in terms of a current that, if maintained in two straight parallel conductors of specific sizes and positions, would produce a certain amount of [magnetic] force between the conductors."[3] Quantitatively, the ampere is defined to be the constant current which will produce an attractive force of 2 × 10–7 newton per metre of length between two straight, parallel conductors of infinite length and negligible circular cross section placed one metre apart in free space.[1][4'][5]

 

from the wikipedia page on the ampere http://en.wikipedia.org/wiki/Ampere

 

a columb is the electric charge that passes through a wire in one second with a current of 1 amp.

 

edit: dammit got ninja'd