Originally posted by jettis
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"The amount of magnetic flux produced by an electrical current flowing through a conductor has no direct relationship to the electrical energy expended as watts "
In a magnetic circuit, the flux is dependent on the magnetomotive force (mmf) quantified as ampere turns (AT). So flux depends directly on current, which needs an electric circuit. As such, one might think a voltage drop across the conductor or coil would indicate power associated with the mmf, however this is dependent on the resistance. And the resistance of the conductor, or coil, can vary for a given current. The resistance of copper wire changing with temperature is a prime example. So as resistance changes, so does power. So the current is not directly (solely) dependent on power. And in modern times, superconductor coils have zero resistance, so obviously no direct dependence on power, so the mmf and flux require zero power in that case.
bi
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