Why Is the Electric Field Inside a Conductor Zero?

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    Electrostatics Principle
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Discussion Overview

The discussion revolves around the principle that the electric field inside a conductor is zero, particularly in the context of electrostatics. Participants explore the implications of this principle and its application to different scenarios, including a uniformly charged sphere.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • One participant expresses confusion regarding the assertion that the electric field inside a conductor is zero, referencing a textbook problem involving a uniformly charged sphere and questioning the movement of charges to the surface.
  • Another participant clarifies that a uniformly charged sphere is not necessarily a conductor, suggesting that the two cases should not be conflated.
  • It is noted that the electric field inside a conductor is indeed zero under electrostatic conditions, provided that there is no current flowing and all charges are stationary.
  • A later reply reiterates that the condition of zero electric field applies only in electrostatics and emphasizes that the original poster's question pertains to this context, thus questioning the relevance of current flow in this case.
  • One participant asserts that the distinction between a spherical charge and a conducting sphere is crucial to understanding the problem at hand.

Areas of Agreement / Disagreement

Participants generally agree that the electric field inside a conductor is zero under electrostatic conditions. However, there is disagreement regarding the applicability of this principle to the scenario of a uniformly charged sphere, with some participants asserting that it is not a conductor and others emphasizing the need to clarify the context.

Contextual Notes

The discussion highlights the importance of distinguishing between different types of charge distributions and the conditions under which the electric field is considered to be zero. There are unresolved assumptions regarding the definitions of conductors and the implications of current flow.

planesinspace
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I seem to be having trouble grasping a very basic principle in electromagnetism. I have been told, in numerous places, that the electric field inside a conductor is zero. (Electrostatics). Yet I keep coming across problems in the textbook like this one:

"Use Gauss's Law to find the electric field inside a uniformly charged sphere (charge density 'ro')."

where for Q[enclosed] = charge density * volume

However, don't all the charges move to the surface of the sphere? and the electric field IN the sphere is subsequently zero?
 
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uniformly charged sphere =/= conductor in all cases.
 
the electric field inside a conductor is zero. (Electrostatics).

Yes this is true so long as there is not current flowing - all charges are stationary.

As soon as a current flows there is a field.
 
Studiot said:
Yes this is true so long as there is not current flowing - all charges are stationary.

As soon as a current flows there is a field.

The OP did indicate that this is Electrostatics. So there is no need to make such qualification.

Feldoh has sufficiently answered the question here, that just because one has a spherical charge, it doesn't mean that one also has a conducting sphere.

Zz.
 

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