Why Does Charge Only Distribute on the Outer Surface of a Conducting Shell?

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Discussion Overview

The discussion centers on the distribution of charge on a conducting shell, specifically why excess charge resides only on the outer surface rather than the inner surface. Participants seek intuitive explanations alongside the theoretical framework provided by Gauss's Law, exploring the implications of charge interactions and electric fields.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant questions why charge does not distribute on the inner surface of a conducting shell, seeking a physical reason beyond theoretical explanations.
  • Another participant suggests that if charge were placed on the inner surface, the mutual repulsion among charged particles would create a net outward force, pushing them to the outer surface.
  • A follow-up comment reiterates the idea of mutual repulsion but questions whether it is possible to have charge on both surfaces while maintaining separation due to this repulsion.
  • Another participant counters that repulsion would not occur unless there is a non-zero electric field, noting that points on the interior surface are within the electric field of the exterior surface's charge distribution.

Areas of Agreement / Disagreement

Participants express differing views on the possibility of charge residing on both the inner and outer surfaces, indicating a lack of consensus on the intuitive understanding of charge distribution in this context.

Contextual Notes

The discussion highlights assumptions regarding electric fields and charge interactions, with some participants relying on Gauss's Law while others seek more intuitive explanations. The implications of charge distribution and electric field behavior remain unresolved.

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It’s been a long time since I took E&M courses and even thought about these things, but a current thread has led me to question the location of excess charge on a conducting shell. Given that there are two surfaces to which charge can move, why doesn’t some charge also locate on the inner surface? Other than that it is on the outside, what makes the outer surface different from the inner surface as far as determining where charge locates?

I know from Gauss’s Law that the charge must be on the outer surface. I’m just looking for a physical/intuitive reason, hence the B prefix on this thread.
 
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Intuitive reason? Imagine that we were to place charged particles on the inner surface in such a way that there was a uniform charge density on the inner surface. The charged particles would all be repelling one another, so they would experience a net outwards force... And that pushes them to the outer surface.
 
Nugatory said:
Intuitive reason? Imagine that we were to place charged particles on the inner surface in such a way that there was a uniform charge density on the inner surface. The charged particles would all be repelling one another, so they would experience a net outwards force... And that pushes them to the outer surface.

Yes, so charge can't just be on inner surface. But couldn't we still consider charge on both the inner and outer surfaces such that the mutual repulsion was keeping them separated?
 
pixel said:
But couldn't we still consider charge on both the inner and outer surfaces such that the mutual repulsion was keeping them separated?
You won't get any repulsion unless there is a non-zero electrical field. All points on the interior surface are inside of the uniform spherical distribution of charge on the exterior surface. What is the electrical field inside of a uniform spherical charge distribution?
 

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