A Question about potential difference in Wire

AI Thread Summary
Charges in a wire move due to the electric field created at its ends, with higher electric potential near the positive terminal. In an ideal conductor, the full voltage drop occurs across the load, while in a real wire, the voltage drop is distributed along the wire, leading to a slight decrease in potential as you move away from the positive terminal. The concept of equipotential surfaces is crucial, as any test charge will spread out over the conductor's surface. Understanding the stable state of the circuit is essential, as dynamic charge redistribution occurs when the circuit is first connected. This redistribution affects the electric and magnetic fields within the circuit.
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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