How do inductors store energy as a magnetic field?

[NascentOxygen]

oh, ok, that makes total sense in that case, so if i have any coil of wire, it will somewhat resist changes in current, just because it takes work to decrease the current in it, which is supplied by the resistance?

It takes work to increase the current in an ideal inductor, and the system returns that energy when you allow the current to decrease. If there is any resistance present it does its usual job of wasting some electrical energy as heat, according to i².R

Thus, it follows that when using any real inductor, to maintain current constant you do have to provide some volts just to overcome the wire's resistance.

 

[anorlunda]

Not if you believe Feynman, as stated above.
Do you have the theory to prove this?

The theory is conservation of energy. The inductor is passive. There is no place for the energy to come from other than the external circuit.

Are we getting hung up on the semantic difference between "external circuit" and "distant charges" ?

 

[berkeman]

I'm going to re-open this thread after some clean-up, because it is starting to address some very advanced and useful concepts about how energy is delivered to a circuit. This is good, IMO

The following quote is from our Mentor discussion about this thread...

The "alternative theory" is an arxiv paper referenced by my2cts in post #57. The paper is here:

http://arxiv.org/abs/physics/0106078

I have only skimmed it and have not checked out the journal it was published in. But at a minimum I would say it is not appropriate for the thread it was posted in.

As for the issue actually being discussed in the thread, it looks to me like anorlunda is saying "the energy stored in the inductor has to be coming from the external circuit", which is true (and obvious from energy conservation), and my2cts is misinterpreting that as meaning "the energy stored in the inductor has to be coming through the wires", which, according to the understanding Doc Al describes (which is also my understanding of the proper application of Maxwell electrodynamics to this case), is not true. But anorlunda is not claiming that it is.

 

[berkeman]

The issue is whether we should split off a more advanced thread. A question to the OP -- @Puglife is your qestion answered?:

 

[my2cts]

Hello Berkeman
I am all for an advanced thread since I am curious about Anorlunda's feedback.