Faraday's Law and Magnetic Induction: cause and effect, experiment and theory

Abstract

Faraday's Law of induction is often stated as "a change in magnetic flux causes an EMF"; or, more cautiously, "a change in magnetic flux is associated with an EMF"; It is as well that the more cautious form exists, because the first "causes" form is incompatible with the usual expression $V=-{\partial }_t\Phi$. This is not, however, to deny the causality as reasonably inferred from experimental observation - it is the equation for Faraday's Law of induction which does not represent the claimed cause-and-effect relationship. Here I investigate a selection of different approaches, trying to see how an explicitly causal mathematical equation, which attempts to encapsulate the "a change in magnetic flux causes ..." idea, might arise.

9 pages, 7 figures

References in corpus (4)

• From least action in electrodynamics to magnetomechanical energy -- a review
• Faraday Induction and the Current Carriers in a Circuit
• Dispersion in time and space: what propagating optical pulses in time (& not space) forces us to confront
• Time and space, frequency and wavevector: or, what I talk about when I talk about propagation