Conductors in large electric fields

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Discussion Overview

The discussion revolves around the behavior of conductors placed in large electric fields, particularly focusing on the limits of opposing electric fields generated by the charges within the conductor. Participants explore the implications of exceeding these limits, including potential changes in the conductor's properties and the physical consequences of such scenarios.

Discussion Character

  • Exploratory, Debate/contested, Conceptual clarification

Main Points Raised

  • One participant states that charges inside a conductor will relocate to cancel the external electric field, resulting in a zero field inside the conductor.
  • Another participant suggests that if the external electric field exceeds the conductor's maximum opposing field, it could lead to ionization and structural failure of the conductor.
  • A different viewpoint posits that exceeding the opposing field might cause the conductor to behave like an insulator, as the external field could pin down the free charges.
  • Some participants mention field emission, where electrons could be emitted from the conductor's surface, potentially leading to phenomena like arcing.
  • One participant counters the insulator claim, asserting that the bulk of the metal remains a conductor despite the external field's influence.

Areas of Agreement / Disagreement

Contextual Notes

gralla55
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You place a conductor in an electric field. The charges inside the conductor will relocate, to form an opposing electric field which cancels the outside field, making the field inside the conductor zero.

However, surely there's a limit to how big an opposing field the charges in the conductor can create. My question is, what will happen if you place a conductor in an electric field larger than the conductors maximum opposing inside field?
 
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Offhand I'd say you would ionize the conductor and rip it apart.
 
gralla55 said:
My question is, what will happen if you place a conductor in an electric field larger than the conductors maximum opposing inside field?

I would guess it not longer behaves as a conductor. Being a conductor means you have free and mobile charges. If your external field has pinned down all your charges then you now have an insulator.
 
Drakkith said:
Offhand I'd say you would ionize the conductor and rip it apart.
Right, you get field emission, which is the emission of electrons from the conducting surface. Eventually you could get an arc (lightning bolt).

ModusPwnd said:
I would guess it not longer behaves as a conductor. Being a conductor means you have free and mobile charges. If your external field has pinned down all your charges then you now have an insulator.
No, the bulk metal is still a conductor.
 
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