How Does Current Flow in an Equipotential Conductor?

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Discussion Overview

The discussion centers around the behavior of current in conductors, particularly in the context of equipotential conductors and the conditions under which charges flow. Participants explore concepts related to electrostatics, potential difference, and Kirchhoff's laws, examining how these principles apply to real-world scenarios.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants assert that a conductor is equipotential and that charges do not flow through it unless there is an external source maintaining a potential difference.
  • Others clarify that in electrostatic equilibrium, there is no net electric field within the conductor, leading to a constant electric potential, and thus no current flows.
  • It is noted that if a conductor is not in electrostatic equilibrium, a net electric field exists, which can cause current to flow due to a potential difference.
  • Some participants question the application of Kirchhoff's laws, pointing out that potential difference across a wire is often considered zero, leading to confusion about current flow.
  • One participant emphasizes that while it may seem that current cannot flow in an equipotential, it is more accurate to say that without a driving potential difference, current will not flow.
  • There is a discussion about how resistance is represented in circuit diagrams, with some participants arguing that the resistance of a real conductor is accounted for by resistor elements in the circuit.

Areas of Agreement / Disagreement

Participants express differing views on the implications of equipotentiality for current flow, with no consensus reached on how Kirchhoff's laws apply in this context. The discussion remains unresolved regarding the interpretation of potential difference in relation to current flow in conductors.

Contextual Notes

Limitations include varying interpretations of electrostatic conditions, the role of potential difference, and the representation of resistance in circuit analysis. These factors contribute to the complexity of the discussion without definitive resolutions.

ajaysabarish
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i have studied that a conductor is equipotential and charges don't flow through it but how does it flow through a wire?
 
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ajaysabarish said:
i have studied that a conductor is equipotential and charges don't flow through it but how does it flow through a wire?

It is because there is an external "source" that keeps one end of it at one potential, and the other end at another potential.

Note that the conductor does not have zero resistance for this to occur.

Zz
 
ajaysabarish said:
and charges don't flow through it
I think you may be talking about a conductor in electrostatics.
 
Also note that if the conductor is in electrostatic equilibrium, then there is no (net) electric field on the charged particles inside (hence a constant electric potential). This means that if the conductor is not in electrostatic equilibrium, then there is a (net) electric field on the charged particles inside, and thus, a potential difference, which causes current.
 
ZapperZ said:
It is because there is an external "source" that keeps one end of it at one potential, and the other end at another potential.

Note that the conductor does not have zero resistance for this to occur.

Zz
but potential difference across a wire(conductor) is taken as zero while writing kirchhoffs law?so there is no potential difference hence charges shouldn't flow through it
 
Prannu said:
Also note that if the conductor is in electrostatic equilibrium, then there is no (net) electric field on the charged particles inside (hence a constant electric potential). This means that if the conductor is not in electrostatic equilibrium, then there is a (net) electric field on the charged particles inside, and thus, a potential difference, which causes current.
but potential difference across a wire(conductor) is taken as zero while writing kirchhoffs law?so there is no potential difference hence charges shouldn't flow through it
 
Dale said:
I think you may be talking about a conductor in electrostatics.
iam talking about both,just comparing them.
 
ajaysabarish said:
but potential difference across a wire(conductor) is taken as zero while writing kirchhoffs law?so there is no potential difference hence charges shouldn't flow through it

Try doing Kirchoff law on such a circuit, i.e. with a zero-resistance conductor connecting the ends of a battery. You will have a SHORT!

Zz.
 
ZapperZ said:
Try doing Kirchoff law on such a circuit, i.e. with a zero-resistance conductor connecting the ends of a battery. You will have a SHORT!

Zz.
yes,so shouldn't it have a resistance,but why don't we take it during kirchhoffs law
 
  • #10
ajaysabarish said:
yes,so shouldn't it have a resistance,but why don't we take it during kirchhoffs law

Because you are representing the resistance in a REAL conductor via the resistor element/s in the circuit. This way, the "line" that you use to connect one element to the next is nothing more than a schematic representation of the path connecting one element to the other!

Zz.
 
  • #11
It is incorrect to say that electrons will not flow in an equipotential, or that current will not flow in a equipotential. It is more correct to say that at in an equipotential there is nothing driving the current. For example you connect one terminal of a voltage source to a set of electrical components with a connecting wire. No current will flow, because everything will be at the same potential.
Now connect (with a wire) the electrical components to the other terminal of the voltage source. (This provides a return path to the voltage source). Because the two terminals of the voltage source are at different potentials, this time current will flow through the electrical components. The voltage difference between the terminals of the voltage source drives the current. The voltage difference will be distributed through the electrical components in proportion to their resistances or reactances.
Note a return path may not be needed of one end that is not connected to the voltage source is connected to a ground wire. (Be careful, if working with harmful voltage, that you (your body and/or wet feet) do not supply the return path to the ground)
 

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