The electric field of infinite sheets

Click For Summary

Discussion Overview

The discussion revolves around the electric field generated by an infinite sheet of uniform positive charge and its interaction with an infinite, uncharged conducting sheet. Participants explore the behavior of induced charges and the resulting electric fields both between and beyond the sheets, focusing on theoretical implications and applications of Gauss's law.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant proposes that the uniformly charged sheet induces a uniformly distributed negative charge on the conducting sheet, particularly on the side closer to the charged sheet.
  • Another participant suggests that the induced positive charge on the conducting sheet will be located on the outer surface, away from the charged sheet, and that this distribution will lead to a zero electric field inside the conducting sheet.
  • A participant questions how the distribution of induced charges can result in a zero electric field inside the conductor, given the presence of both positive and negative surface charges.
  • One response asserts that the electric field inside the conducting sheet is zero because the field due to the charged sheet is exactly canceled by the field from the induced charges.

Areas of Agreement / Disagreement

Participants express differing views on the nature of the electric field inside the conducting sheet, with some asserting it is zero due to cancellation, while others question this conclusion, indicating that multiple competing views remain unresolved.

Contextual Notes

The discussion includes assumptions about the behavior of electric fields in conductors and the distribution of induced charges, which may depend on specific conditions or definitions not fully explored in the thread.

Conservation
Messages
63
Reaction score
0
I am trying to understand electric fields of conductors.

Say that there is an infinite sheet of uniform positive charge; parallel to it lies a infinite, uncharged conducting sheet. What would the field look like between the sheets? Beyond the sheets? I would guess that the uniformly charged sheet would induce a uniformly distributed negative charge on the conducting sheet on the side closer to it, but I don't understand how the induced positive charge would distribute itself in the conducting sheet. Or how the positive charge would then affect the field.

Thanks.
 
Physics news on Phys.org
Conservation said:
but I don't understand how the induced positive charge would distribute itself in the conducting sheet. Or how the positive charge would then affect the field.
It will be on the other surface(outer surface, far from the sheet) of the conducting sheet. These induced charges will make the E field inside the conducting sheet 0. Electric field lines from the charged sheet will terminate at the -ve induced charge on the conducting sheet and will reappear from the +ve induced charge on the other surface of the conducting sheet.
 
  • Like
Likes   Reactions: Conservation
Okay. That makes sense; That would make E field coming out from the opposite surface same as the E field going in, and that's consistent with Gauss's law.

What I fail to see is how this distribution of induced charges will result a field of 0 inside the conductor. If there is an infinite positive surface charge on one side of the conducting sheet and infinite negative surface charge on the other side of the conducting sheet, shouldn't there be a field inside the conducting sheet?
 
Conservation said:
shouldn't there be a field inside the conducting sheet?
Yes. And that field exactly cancels the field due to the charged sheet, making net E field inside the conducting sheet zero. This is why electric field inside a conductor placed in an external electric field is always 0.
 
  • Like
Likes   Reactions: Conservation

Similar threads

  • · Replies 22 ·
Replies
22
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 3 ·
Replies
3
Views
718
  • · Replies 32 ·
2
Replies
32
Views
2K
  • · Replies 18 ·
Replies
18
Views
2K
  • · Replies 14 ·
Replies
14
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K