Electric field strength between charged plates

Click For Summary

Homework Help Overview

The discussion revolves around understanding electric field strength between charged plates, particularly focusing on the relationship between distance and electric field strength as described by the equation E=kq/r². Participants are exploring the implications of this equation in the context of parallel plate capacitors.

Discussion Character

  • Exploratory, Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants discuss the relationship between distance and electric field strength, questioning the validity of the equation used for different geometries. There is an exploration of field line sketches and their implications on field strength.

Discussion Status

Some participants have provided guidance on considering field line density and geometry, suggesting that the original poster may need to rethink their approach based on the specific setup of parallel plates. There is an acknowledgment of different electric field behaviors depending on the configuration.

Contextual Notes

Participants are discussing the application of the equation for point charges versus the scenario of parallel plates, indicating a potential misunderstanding of the underlying principles. There is also mention of Gaussian surfaces, suggesting a broader context of electrostatics being relevant to the discussion.

Cici2017

Homework Statement


Screen Shot 2017-07-31 at 6.50.30 pm.png


Homework Equations

The Attempt at a Solution


E=kq/r2
so when the distance increase E should decrease?
I know this is wrong, but can someone explain why? Thanks
 
Physics news on Phys.org
Cici2017 said:

Homework Statement


View attachment 208034

Homework Equations

The Attempt at a Solution


E=kq/r2
so when the distance increase E should decrease?
I know this is wrong, but can someone explain why? Thanks
Have you tried sketching the field lines?
 
haruspex said:
Have you tried sketching the field lines?
field lines are from + to negative. vertical.
 
Cici2017 said:
field lines are from + to negative. vertical.

The field strength is equal to the density of the field lines, what can you say about that if all the field lines are vertical?
 
Have you covered gaussian surfaces in electrostatics yet?
 
Cici the field at any point depends, amongst other things, on the geometry of the system. The equation you used gives the field due to an isolated point charge. And yes,this particular field does weaken with distance. The field for other geometries is different so for your parallel plates take the advice given above.
 
I think I have got it. Thank you!
 

Similar threads

Why is electric field at the center of a charged disk not zero?
  • · Replies 4 ·
Replies
4
Views
4K
Electric field strength near a metal plate
  • · Replies 4 ·
Replies
4
Views
5K
Electric field between capacitor plates when a dielectric slab is inserted
  • · Replies 14 ·
Replies
14
Views
3K
Electric displacement field density equation
  • · Replies 1 ·
Replies
1
Views
1K
Electric field strength at a point due to 3 charges
  • · Replies 3 ·
Replies
3
Views
2K
How does the presence of a dielectric change the max V of a capacitor?
  • · Replies 6 ·
Replies
6
Views
3K
Finding electric field between two conducting plates using Gauss' law
  • · Replies 4 ·
Replies
4
Views
3K
Confused about direction of electric field
  • · Replies 7 ·
Replies
7
Views
3K
Two different dielectrics between parallel-plate capacitor
  • · Replies 6 ·
Replies
6
Views
2K
Understanding Electric Field of Positive & Negative Plates
  • · Replies 2 ·
Replies
2
Views
2K