I would like to ask you the question again Poynt.

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

As long as the current flowing is increasing or decreasing over time, the answer to both is yes.

It is an inductor...

PW

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

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.

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

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

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


Brad

When the supply is first connected or turned on (T=0) the voltage measured across the inductor will essentially be whatever the V supply voltage is.

It is still an inductor with reactance, and it will take time for the current flow to build.

PW

You have not answered the question asked in the diagram below.


Brad

I believe I did answer the question.

However, if you are referring to DC conditions, the answer would be no.  But under time varying conditions, as in when you first connect the supply, the answer is yes.

As this relates to MH's original question, at T=0 there is a measurable voltage across the inductor.

PW