EMF in a loop confusion

Question

When one has a loop of wire in a changing magnetic field (or a rotating wire loop in a constant magnetic field), Faraday's law says that an EMF -- i.e. a potential difference -- is created. But what does it mean for a loop of wire to have a potential difference? A loop of ideal wire should be an equipotential so unless we have to throw out the notion of ideal wire in this case, I don't see how a potential difference could but created in a single length of wire.

Note that I do understand that a current is created. And I can do the calculations in Faraday's law. I'm just looking for an explanation for what a potential difference in a single loop of wire is supposed to mean.

Answer 1

This scenario is why EMF and potential difference are not the same.

Electrostatic potential is only defined in situations where there is no magnetic induction. In such cases, then a potential field can be uniquely defined, and we can talk about potential difference, etc.

But when there is a varying magnetic field, and thus an induced current (or more strictly curl of the electric field is non-zero, the electrostatic potential is not a defined quantity, and we can only talk about an EMF generated in the loop.

So it's totally expected that with a loop in a varying magnetic field, you can't define a unique potential at each point on the wire.