A Question about potential difference in Wire

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Discussion Overview

The discussion revolves around the concept of electric potential in a circuit, specifically addressing how potential difference behaves along a wire connected to a power source. Participants explore the implications of ideal versus real conductors and the concept of voltage division in circuits.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant states that electric potential is higher near the positive terminal and questions why it does not decrease as one moves away from it, suggesting a misunderstanding of potential distribution in a circuit.
  • Another participant introduces the concept of "voltage division" for resistances in series, implying that potential differences can vary across components in a circuit.
  • A third participant clarifies that if the wire is an ideal conductor, the full voltage drop occurs across the load, while in a real wire with resistance, the voltage drop occurs linearly along the wire.
  • Another participant emphasizes the need to model the wire as an equipotential surface and discusses the dynamic redistribution of charge, suggesting that understanding stable states is crucial for analyzing the circuit's behavior.

Areas of Agreement / Disagreement

Participants express differing views on how electric potential behaves in a circuit, with some supporting the idea of uniform potential in ideal conditions and others highlighting the effects of resistance and real-world conditions. The discussion remains unresolved regarding the implications of these differing models.

Contextual Notes

Participants note the importance of distinguishing between ideal and real conductors, as well as the role of dynamic processes in understanding electric potential distribution. There are unresolved assumptions regarding the nature of the wire and the conditions under which the potential is analyzed.

Kaneki123
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Okay...I got a question. Charges move in a wire due to an electric field across its ends. Now, positive test charge in an electric field would have higher electric potential nearer to the positive plate than anywhere else. Now in case of a circuit, like the one I have drawn, the electric potential at any point between A to D is the same (please point out if there is something wrong in the statement. My question is the, as we move further away from the positve terminal, the electric potential should decrease, so why does it not??...If someone could point out potential differences at the different points in the circuit, that'd be helpful...Any help is appreciated
 

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Kaneki123 said:
Okay...I got a question. Charges move in a wire due to an electric field across its ends. Now, positive test charge in an electric field would have higher electric potential nearer to the positive plate than anywhere else. Now in case of a circuit, like the one I have drawn, the electric potential at any point between A to D is the same (please point out if there is something wrong in the statement. My question is the, as we move further away from the positve terminal, the electric potential should decrease, so why does it not??...If someone could point out potential differences at the different points in the circuit, that'd be helpful...Any help is appreciated
Are you familiar with the concept of "voltage division" for resistances in series? :smile:
 
Hi,
Kaneki123 said:
My question is the, as we move further away from the positve terminal, the electric potential should decrease, so why does it not
First we have to make clear if the wire is an ideal conductor.
If it is, the full 12 V voltage drop occurs in the bulb (DE)
If it is a real wire (a thin wire with non-zero restance), voltage drop occurs linearly between A and D and also between E and G, so the the voltage drop between D and E is slightly less than 12 V.
 
You need to model your wire as an equipotential surface. Any test charge will spread out over the metal surface to effectively charge the capacitance of that surface.

It is a mistake to use dynamic ideas to understand stable situations. You need to consider a stable state, or the dynamic transition towards that stable state.

The dynamic redistribution of charge in time involves the inductive and capacitive geometry of the circuit. Energy from the battery will begin to be distributed into the electric field when the circuit is first connected. That initial redistribution of charge and the resulting continuous flow of charge through the light globe will distribute energy into the magnetic field.
 

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