Electric Field in 3 Parallel Plates

Click For Summary
SUMMARY

The electric field at point A between three parallel plates is calculated to be 1.5σ/ε0. The approach involves summing the contributions from each plate, resulting in an effective charge density of 3σ. This is confirmed through both direct calculation and the application of Gauss's law, where the net free charge within a Gaussian surface leads to the same conclusion of E = (3/2)σ/ε0.

PREREQUISITES
  • Understanding of electric field concepts
  • Familiarity with Gauss's law
  • Knowledge of charge density (σ) and permittivity (ε0)
  • Basic algebra for manipulating equations
NEXT STEPS
  • Study the application of Gauss's law in different geometries
  • Explore electric field calculations in capacitors
  • Learn about the effects of dielectric materials on electric fields
  • Investigate the behavior of electric fields in non-uniform charge distributions
USEFUL FOR

This discussion is beneficial for physics students, educators, and anyone studying electrostatics, particularly those focusing on electric fields and charge distributions in parallel plate configurations.

Broem
Messages
9
Reaction score
0

Homework Statement


What is the electric field at point A in the unit of σ/ε0?


Homework Equations


E=σ/2ε


The Attempt at a Solution


I just want to make sure my thinking behind this is correct.
From the center we have +5σ. To find the A what I did is subtract the other two -σ from the 5: this gives me 5-1-1 = 3.
From here I just plug in: 3σ/2ε which in the units = 1.5 σ/ε

Is this the correct approach?
 

Attachments

  • three-plates-exam.jpg
    three-plates-exam.jpg
    11.7 KB · Views: 1,273
Physics news on Phys.org
Yep.
 
Alternative sol'n: if you put a Gaussian box of area = 1m^2 and running from A to D, the inside net free charge is 3σ C and the total flux area is 2 m^2 (no flux out the other 4 sides if the plates are infinite in dimension).

That would make εE*2m^2 = 3σ so E = (3/2)σ/ε. Same answer!
 

Similar threads

  • · Replies 58 ·
2
Replies
58
Views
6K
Replies
4
Views
1K
  • · Replies 4 ·
Replies
4
Views
6K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 20 ·
Replies
20
Views
4K
  • · Replies 4 ·
Replies
4
Views
1K
  • · Replies 17 ·
Replies
17
Views
3K
  • · Replies 10 ·
Replies
10
Views
5K