newton per metre of its length. [P4.3]
is: the SI unit of electric current (i.e. rate of flow of electric charge), one of the seven base units. [P4.1]
is defined: as that constant current which, if maintained in each of two infinitely long, straight, parallel wires of negligible cross section, placed 1 metre apart, in a vacuum, will cause each wire to experience a force of magnitude newton per metre of its length. [P4.3]
is equivalent: to the transfer of one coulomb per second, so 
[P4.1]
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