Does the pointing vector theory hold true for DC current?

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Discussion Overview

The discussion centers around the nature of electric current in circuits, particularly in relation to direct current (DC) and the implications of using electrical devices. Participants explore concepts such as the flow of charge, the role of resistance, and the relationship between current and energy consumption.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • Some participants assert that current and charge do not get used up in a circuit, emphasizing that the same amount of charge enters and exits the circuit.
  • Others argue that while current remains constant in a continuous circuit, resistive devices reduce the flow of current, leading to energy dissipation as heat or light.
  • Several participants discuss the role of power companies, suggesting that they charge for the work done to maintain voltage and current flow, rather than for the electrons themselves.
  • There are claims that energy is converted to other forms (e.g., heat, light) in electrical devices, which some participants interpret as a reduction in current flow.
  • Some participants challenge the idea that current can be "used up," suggesting that confusion exists between current and energy consumption.
  • Disagreements arise regarding the impact of resistive devices on current flow, with some asserting that current is reduced at the location of the device, while others maintain that the current remains constant throughout the circuit.

Areas of Agreement / Disagreement

Participants express multiple competing views on the nature of current flow and energy consumption in electrical circuits. There is no consensus on whether current can be considered as being "used up" or reduced in the presence of resistive devices.

Contextual Notes

Participants reference concepts such as Kirchhoff's current law and the distinction between current and energy, indicating a potential need for clarity in definitions and assumptions regarding these terms.

  • #61
Let me ask of you this. Can you explain how it works WITHOUT using either of the terms energy or power? Neither of them really explain anything to me. (And I don't think they either of them can "flow" since they aren't physical objects)
 
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  • #62
Drakkith said:
Let me ask of you this. Can you explain how it works WITHOUT using either of the terms energy or power? Neither of them really explain anything to me. (And I don't think they either of them can "flow" since they aren't physical objects)

Firstly, is anything, a truly 'physical object' except in as far as you can sort of identify it as having a localised region of influence? Is the wave function of an electron when it's in a bound state 'really' a physical object?

If someone 'generates' some Power in a Power Station and someone uses that Power in their home then something can be said to have 'flowed' from A to B.

Surely this thread can't get us anywhere because all we are doing is comparing various models, some of which are better than others.
 
  • #63
sophiecentaur said:
Firstly, is anything, a truly 'physical object' except in as far as you can sort of identify it as having a localised region of influence? Is the wave function of an electron when it's in a bound state 'really' a physical object?

If someone 'generates' some Power in a Power Station and someone uses that Power in their home then something can be said to have 'flowed' from A to B.

Surely this thread can't get us anywhere because all we are doing is comparing various models, some of which are better than others.

We can start by using terms that actually describe something useful. Saying power flows through the line says absolutely nothing about what is occurring unless you already know how it works. And please, spare the "is anything truly physical" BS.
Surely this thread can't get us anywhere because all we are doing is comparing various models, some of which are better than others.
How else would you get to the answer? Comparing models and asking questions about them seems like a very good way to learn.
 
  • #64
"The answer"?
I think this thread is not about answers as much as 'use mine'. But I suppose that goes for many of our threads.
The question of whether or not Power flows 'through' or 'along' or 'because the line is there' is one of those 'really' questions. Without some current flowing, there is no power transfer and so it seems to be reasonable to associate the two. I did wonder about the comment on the Power being due to magnetic fields - that doesn't take the transmission voltage into account or the fact that DC through a Transformer winding (high B field) would, somehow, be different from power along a straight wire of the same resistance.

I do agree that the 'pushing electrons through' / quasi hydraulic idea has to be dodgy.
 
  • #65
Without some current flowing, there is no power transfer and so it seems to be reasonable to associate the two.
Which is why I am asking to avoid talking about energy or power. Neither of those terms refer to anything specific, but only to the overall effect. I KNOW power flows from here to there or whatever, but I don't know how. And I agree that there are no absolute answers, but only answers of varying accuracy.
 
  • #66
sophiecentaur said:
"The answer"?
I did wonder about the comment on the Power being due to magnetic fields - that doesn't take the transmission voltage into account or the fact that DC through a Transformer winding (high B field) would, somehow, be different from power along a straight wire of the same resistance.

That comment led me to think about a simple experiment which can hopefully test the validity of the pointing vector theory for a dc current.
However I will start a new thread because it’s drifting to far from the op. Hope to see you and Drak back in the general section.
 

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