MH's ideal coil and voltage question

[Pirate88179]

I think this is an example of the root cause of one of Brad's problems:

<<< Why can a voltage not exist across a shorted ideal inductor that has current flowing through it>
Because V=IxR,and R=0  >>>

He keeps on going back to Ohm's law for an inductor.  He hears "an inductor has no resistance when DC current is flowing through it" then he says "R=0" and then he says the current must be infinity.  At least sometimes he says that.

So I don't think he can make a distinction between the special condition where an inductor manifests zero resistance and Ohm's law and zero ohmic resistance.

Assuming that I am correct perhaps someone can lead him out of that quagmire.

MileHigh

Well, that depends.  Is it an ideal Quagmire?  If so, it will be bottomless and have infinity adhesion qualities.  By definition, no one can ever escape an ideal quagmire...if they could, then it would have not be an ideal one.


Bill

PS  Hopefully it is obvious that I am just attempting a bit of humor.  It is, of course, not ideal humor, otherwise everyone would be laughing which I am sure they are not.  It is Friday and it has been a long, hard week and I am just blowing off a bit of steam over here.

[MileHigh]

You are making me think of the Flintstones and the moaning dinosaurs trapped in the tar pits.

[picowatt]

I would like to see you do that PW.
Th inductor is a continual loop,and so the current would flow in both directions from the positive connection,to the negative.
the magnetic field produced by one half of the windings would be equal and opposite to that of the field produced by the other half of the windings. So there would be no inductive effect. Than now leaves you with only the resistance in which a voltage can be seen across,and the resistance value is 0.


Brad

Do you believe you can you induce a current flow in an "ordinary" inductor with its ends shorted together?

PW

[MileHigh]

Brad, the short answer is that you can always place a voltage source across an ideal inductor even if it has "zero resistance."  The moment you place a voltage source across an inductor it acts as an impedance and the voltage really exists, and the current starts to change.

[tinman]

The question for you MH

1-If we have an inductor that has no resistance,and the two ends of that inductor are joined,so as the inductor is now just a continual loop of wire(shorted),can we place a voltage across that inductor that has no resistance.
2-If there is now a current flowing in that shorted ideal inductor,is there any two points across that ideal inductor where a voltage can be measured?


Brad

I have made the question very simple MH--see diagram below.


Brad