Integral form of Gauss' Law, Parallel Plate Capacitor

Click For Summary
SUMMARY

The integral form of Gauss' Law does not provide useful information for a parallel plate capacitor with vacuum between its plates when applied to a closed surface that does not intersect either plate. While Gauss' Law holds true mathematically, stating that the total charge within the surface is zero, it fails to yield specific values for electric field (E), surface charge density (σ), or total charge (Q) due to the nature of integration over the entire surface area. The discussion emphasizes the distinction between the validity of a law and its practical utility in solving electrostatic problems.

PREREQUISITES
  • Understanding of Gauss' Law and its mathematical formulation.
  • Familiarity with electric fields and charge distributions.
  • Knowledge of parallel plate capacitors and their characteristics.
  • Basic calculus skills for integration and surface area calculations.
NEXT STEPS
  • Study the application of Gauss' Law in systems with high symmetry, such as spherical and cylindrical charge distributions.
  • Learn how to calculate electric field (E) and surface charge density (σ) using alternative methods, such as direct integration of charge distributions.
  • Explore the limitations of Gauss' Law in non-uniform electric fields and complex geometries.
  • Investigate the relationship between electric flux and electric field in various configurations, including capacitors in different media.
USEFUL FOR

Students of electromagnetism, physics educators, and electrical engineers seeking to deepen their understanding of electrostatic principles and the practical applications of Gauss' Law in capacitor systems.

jajay504
Messages
8
Reaction score
0

Homework Statement


If one were to consider a parallel plate capacitor with a distance d between them connected to a battery and a vacuum space between the plates. Will the integral form of Gauss' Law to any closed surface between the plates that does not cross either plate hold? If not, what in Gauss' Law would prevent this from working?

Homework Equations



Gauss' Law

The Attempt at a Solution


I know that Gauss' law works in cases where there is high degree of symmetry.
I also know that the integral form describes an integration of fields. However, after a function is integrated, a lot of information is lost. A non-zero charge density cannot, under any circumstances, give rise to a an electric field that vanishes everywhere.

 
Physics news on Phys.org
There's a distinction between a Law being valid (ie, "holding" true), and being useful.
Gauss' Law would merely say that there's zero total charge inside the surface ... which we already knew ... there's only vacuum in there, after all.
But since you need to integrate over the whole surface Area, you can't find the flux inward thru the top separately from the flux that leaves out the bottom => so you can't find the surface charge density. It still "works" in the sense that it doesn't lie ("0=0"), but it doesn't "work" in the sense of being useful to solve for E, or σ, or Q ...
 

Similar threads

Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
9
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 12 ·
Replies
12
Views
2K
  • · Replies 26 ·
Replies
26
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
Replies
11
Views
4K
Replies
9
Views
3K