What is happening in those wires?

Berzerker

Joined Jul 29, 2018
542
MrChips said:
Then I sincerely suggest that you teach some other subject and not electricity and electronics.
:)

It's "magic" use Abracadabra or Alakazam when trying to explain it !
Hand gestures are a must ! Presentation is everything !
Brzrkr
 

Thread Starter

Gerry Rzeppa

Joined Jun 17, 2015
170
Perhaps the answer you are seeking is the electron concentration at wire B is higher than that at wire A.
Well, that seems simple enough. Let me make sure I've got it right:

At the beginning of the discharge period, there are more electrons in wire B than wire A, which accounts for the potential difference between the two wires. As these "excess" electrons flow from the wire B leg of the circuit to the wire A leg of the circuit, the difference in the number of electrons decreases (reducing the potential difference) and eventually the electron counts practically equalize causing the potential difference to approach zero. Yes?

Wire A and wire B are practically equivalent. We do not consider charge concentration as a physical difference.
If it's not a physical difference, what kind of difference is it? I always thought an ion was physically different from a non-ion specifically because it had a different number of electrons.
 

Berzerker

Joined Jul 29, 2018
542
My point was kinda sarcastic. But think about when your not looking at photons that are being split ? as long as you look at them they split....
The minute you don't, they don't ? Or one atom knowing what another does light years away in that very same moment ?
You think about it ?
Brzrkr
 

MrChips

Joined Oct 2, 2009
19,270
If it's not a physical difference, what kind of difference is it? I always thought an ion was physically different from a non-ion specifically because it had a different number of electrons.
Just because you remove an electron does not make the atom or molecule an ion.

We are referring to the movement of electrons in metallic conductors. Electric current in a conductor is the effect of free electrons which you can imagine as a cloud. The atoms of the metal do not become ions.
 

Thread Starter

Gerry Rzeppa

Joined Jun 17, 2015
170
Just because you remove an electron does not make the atom or molecule an ion.

We are referring to the movement of electrons in metallic conductors. Electric current in a conductor is the effect of free electrons which you can imagine as a cloud. The atoms of the metal do not become ions.
Okay, fine. I'd prefer to stick to the original question, if you don't mind. Is the following correct?

At the beginning of the discharge period, there are more "free" electrons (higher electron concentration) in wire B than wire A, which accounts for the potential difference between the two wires. As these "excess" electrons flow from the wire B leg of the circuit to the wire A leg of the circuit, the difference in the number of electrons decreases (reducing the potential difference) and eventually the free-electron counts practically equalize causing the potential difference to approach zero. Yes?
 

BobTPH

Joined Jun 5, 2013
2,017
There is no difference between the two wires. The difference is that they are at different electric potentials. That difference is caused by the electric field between the two plates of the capacitor.

Bob
 

Berzerker

Joined Jul 29, 2018
542
@GerryRzeppa
Has left the building.
I don't know if you guys have noticed "BUT" alot of posts have been by new comers (no problem there) "BUT" they are kinda like students trying to be someone they're not to get answers to questions they need ?
You do realize school just started....Right !
Brzrkr
 

Thread Starter

Gerry Rzeppa

Joined Jun 17, 2015
170
There is no difference between the two wires. The difference is that they are at different electric potentials. That difference is caused by the electric field between the two plates of the capacitor.
Let me see if I understand what you're saying. Let's say I have two similar books, A and B, sitting on a table. When I lift book A above the table it is now at a different gravitational potential than book B, but it remains physically unchanged. Likewise, when I connect wires A and B to opposite ends of the charged capacitor, wire A is now at a different electrical potential than wire B, but it remains physically unchanged. The field of which you speak is therefore, at least in some respects, the electrical analog of gravity. Yes?
 

dendad

Joined Feb 20, 2016
2,983
Why do you assume the wires change?
Water pipes don't change depending on the pressure or water flow. (That is assuming it is a good pipe, and below the bursting pressure. Water analogies are not perfect!)
The only change I can think of for the wire could be some heating depending on the current. And maybe their position due to the magnetic field produced.
 
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MisterBill2

Joined Jan 23, 2018
3,859
The wires will be slightly warmer. This temperature rise may not be easily detected, but at least in theory it will exist because some power is lost in the resistance of the wires, unless they are perfect conductors. So in the kingdom of Utopia, where all theories work and conductors have no resistance, there would be no change. In the real world there will be some small change but probably you will not have the equipment to detect or measure it because it will be a very small change.
 

Thread Starter

Gerry Rzeppa

Joined Jun 17, 2015
170
Why do you assume the wires change?
Because the reading on a voltmeter connected across the wires changes throughout the discharge period. So something must be changing in or on or around those wires.

Water pipes don't change depending on the pressure or water flow. (That is assuming it is a good pipe, and below the bursting pressure. Water analogies are not perfect!)
I agree, the pipes themselves don't change, but there is a physical change in the water in the pipes when the pressure is increased (eg, the molecules are more tightly packed, or are more energetic due to heating, etc). So I thought there might be a physical change in the atomic configuration of the the wires when the electrical potential is increased (eg, "more free electrons" or "free electrons vibrating more energetically" or "free electrons pulled further away from protons in the wire" or something like that).

The only change I can think of for the wire could be some heating depending on the current.
Yes, but the increase in heat is an effect, not a cause. As I understand it, the cause is friction between the moving free electrons and the other relatively stationary atoms in the wires.

And maybe their position due to the magnetic field produced.
Do you mean the position of the wires, or the position of the free electrons in the wires? Are you thinking of the field as a cause or an effect?
 

MisterBill2

Joined Jan 23, 2018
3,859
Are you telling us that there is a voltage developed between the ends of each individual wire? And what sort of meter is being used to measure this changing voltage? Now I am questioning the experimental setup. If the capacitor is a reasonable value, perhaps 100 microfarads, and the resistor chosen so that it takes an hour to discharge from a hundred volts to less than one volt, then the resistance of the wires is much smaller than the resistor "R", and the current is very low. Of course, if this experiment is being done with a simulation program then all bets are off and there is no hope of a correct understanding of whatever is happening.
In the real world there will not be enough current in those wires after the first minutes to be measured with normal measuring equipment. So if the results are showing that a voltage is being developed along the length of the wire then there is an error in the experiment.
 

dendad

Joined Feb 20, 2016
2,983
Do you mean the position of the wires, or the position of the free electrons in the wires? Are you thinking of the field as a cause or an effect?
The wires thenselves.
I have seen wires jump due to interaction between the produced magnetic fields with excessive overload currents flowing in them.
No doubt there may be some subatomic changes in the wires, but why do you need this to confuse students with unless they are going to become atomic physicists or something like that?

The only changes I have noticed in wires over my many years of electronics career are due to heating. Wires can change from solid to liquid, and even plasma if you try hard enough ;)

And for the change of the water under pressure, I had always been taught the water is not compressible so I would think it does not change,.
 

SamR

Joined Mar 19, 2019
1,135
Yes, but the increase in heat is an effect, not a cause. As I understand it, the cause is friction between the moving free electrons and the other relatively stationary atoms in the wires.
You teach science?!?! Heat is a measurement of released energy due to the collision of particles. Too many angels around here, I'm going back under my rock to take a nap.
 
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