Does there exist any electric field inside a charged conductor?

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Discussion Overview

The discussion revolves around the existence of electric fields inside charged conductors, particularly in the context of electrostatics and electrodynamics. Participants explore the implications of electric fields on current density and drift velocity of electrons within conductors.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • Some participants assert that there is no electric field inside a conductor, particularly in electrostatic conditions.
  • Others argue that an electric field can exist inside a conductor when considering dynamic situations, such as current flow, referencing Ohm's law.
  • There is a question about whether the discussion pertains to electric fields or electric currents, with some clarifying that both are relevant as the electric field drives the current.
  • One participant notes that while electrostatics assumes no electric field, electrodynamics allows for the presence of an electric field that causes current to flow.
  • Another participant mentions that on an atomic scale, significant electric fields may exist but average out in macroscopic conditions.
  • Several participants emphasize the definitions used in electrostatics, stating that the current density is zero, which implies that the electric field must also be zero in that context.
  • There are requests for elaboration on the relationship between electric fields and current density, indicating some confusion over the concepts.

Areas of Agreement / Disagreement

Participants do not reach a consensus; there are multiple competing views regarding the existence of electric fields inside conductors, particularly when comparing electrostatic and dynamic conditions.

Contextual Notes

Limitations include the dependence on definitions of electrostatics and electrodynamics, as well as the unresolved nature of the relationship between electric fields and current density in different contexts.

Anindya Mondal
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We know that there exists no electric field inside a conductor. But while calculating drift velocity of electrons inside an electric conductor, why do we consider the electrons are present inside the charged conductor?
 
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Anindya Mondal said:
We know that there exists no electric field inside a conductor.
There certainly can exist an electric field inside a conductor. The electric field is proportional to the current density for ordinary conductors. This is known as Ohm's law
 
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Is it electric field or electric current?
 
Anindya Mondal said:
Is it electric field or electric current?
Both. The electric field drives the electric current.
 
What you're referring to is probably what you get told in electrostatics at first, but the lack of an electric field is actually the condition for the static state, it can exist and as mentioned here causes a current to flow, this is now electrodynamics
 
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On the atomic scale there are always significant electric fields but these average out.
 
gau55 said:
What you're referring to is probably what you get told in electrostatics at first, but the lack of an electric field is actually the condition for the static state, it can exist and as mentioned here causes a current to flow, this is now electrodynamics
Yeah, I refer to electrostatics
 
In electrostatics by definition you assume that all fields are time independent and that all current densities are vanishing, ##\vec{j}=0##. Now you have (in non-relativistic approximation) ##\vec{j}=\sigma \vec{E}##, where ##\sigma## is the electric conductivity of your medium. For a conductor ##\sigma \neq 0##, which implies that ##\vec{E}=0##, because in the electrostatic case you have by definition ##\vec{j}=0##.
 
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vanhees71 said:
In electrostatics by definition you assume that all fields are time independent and that all current densities are vanishing, ##\vec{j}=0##. Now you have (in non-relativistic approximation) ##\vec{j}=\sigma \vec{E}##, where ##\sigma## is the electric conductivity of your medium. For a conductor ##\sigma \neq 0##, which implies that ##\vec{E}=0##, because in the electrostatic case you have by definition ##\vec{j}=0##.
I can't understand, please be elaborate.
 
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What don't you understand? It's very simple. In electrostatics by definition the current density vanishes. In a conductor, according to Ohm's Law, the current density is proportional to the electric field and thus the electric field must vanish within the conductor. I don't know, how I can this elaborate more.
 

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