What charges on high voltage circuits?

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SUMMARY

This discussion focuses on the nature of charges in high voltage circuits, specifically addressing the movement of electrons as negative charge carriers. It clarifies that while electrons flow, the conventional definition of current describes the movement of positive charges in the opposite direction. The conversation also touches on the effects of alternating current (AC) on charge movement and its implications for magnetic fields generated by high voltage cables. Notably, the discussion concludes that there is virtually no net charge in a conductive wire despite the flow of electrons.

PREREQUISITES
  • Understanding of electrostatic voltmeters
  • Knowledge of charge carriers, specifically electrons and protons
  • Familiarity with alternating current (AC) and direct current (DC) concepts
  • Basic principles of electromagnetism and magnetic fields
NEXT STEPS
  • Research the principles of charge carriers in electrical circuits
  • Learn about the effects of AC on magnetic fields
  • Explore the historical context of current definitions in electrical engineering
  • Investigate the relationship between current flow and magnetic field generation
USEFUL FOR

Electrical engineers, physics students, and anyone interested in understanding the behavior of charges in high voltage circuits and their implications for magnetic fields.

oem7110
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People usually use an electrostatic voltmeter for direct measurement.
I would like to know what kind of charges is on following high voltage circuits.
Will it be positive or negative charges?
Does anyone have any suggestions?
Thanks in advance for any suggestions

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Charges which flow (current) are always the negative charges. The electrons move, the protons in the nucleus don't really move.

The current, though, is defined as the movement of positive charges in the other direction. This is due to a bad convention that historically people used.
 
Matterwave said:
Charges which flow (current) are always the negative charges. The electrons move, the protons in the nucleus don't really move.

The current, though, is defined as the movement of positive charges in the other direction. This is due to a bad convention that historically people used.

Does it apply AC here? so the charges will change alternatively, so electron and proton does not move a far distance.

If there is a massive negative charges moving along the cable, does it generate any magnetic field? which distorts the north within the compass.
Does anyone have any suggestions?
Thanks you very much for any suggestions
 
oem7110 said:
Does it apply AC here? so the charges will change alternatively, so electron and proton does not move a far distance.

If there is a massive negative charges moving along the cable, does it generate any magnetic field? which distorts the north within the compass.
Does anyone have any suggestions?
Thanks you very much for any suggestions

Always (in a wire anyways), the neucleus doesn't move much. For AC current, it's the electrons that move in alternating directions. A magnetic field is produced, and it is produced even in the constant DC current case.
 
Matterwave said:
Always (in a wire anyways), the neucleus doesn't move much. For AC current, it's the electrons that move in alternating directions. A magnetic field is produced, and it is produced even in the constant DC current case.

So does compass not work very well near the high voltage cable? right?
Thanks everyone very much for any suggestions
 
I've never noticed any influence on a compass when walking under high voltage cable.
I think the needle can't react fast enough to move with the 50 or 60 Hz oscillations of the magnetic field, and the average field will be zero with AC.

Of course, a magnetic field is produced by a high current, so the magnetic field isn't all that big, because the current might be only 1000 A or so, you can't get close to it, and there will be wires with currents in the opposite direction that will cancel out most of the field.
 
What do you mean by "Charge on the circuit"? Virtually, there is no net charge on the circuit or hardly any since wires are highly conductive. Actually, it is a flow of electrons, which carry negative charge, but whenever you take a section of the wire there is no net charge, although electrons are moving.
 

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