Parallel plate capacitor and insulating material

Click For Summary
SUMMARY

The discussion centers on the behavior of a parallel-plate capacitor with a glass insulating layer, specifically examining how its discharge characteristics depend solely on the insulating material's properties rather than its dimensions. The capacitor has plates with an area of 10 cm² and is separated by a 0.10 mm layer of glass, which has a resistivity of 1.2 x 10¹³ Ω·m and a dielectric constant of 5.6. The time constant for the capacitor's discharge through the insulation is calculated to be 590 seconds, demonstrating that the RC time constant is independent of the capacitor's cross-sectional area.

PREREQUISITES
  • Understanding of parallel-plate capacitor fundamentals
  • Knowledge of resistivity and its impact on current leakage
  • Familiarity with capacitance equations, specifically C = emf(A/d)
  • Basic concepts of time constants in RC circuits
NEXT STEPS
  • Study the relationship between resistivity and current leakage in insulating materials
  • Explore the derivation of the time constant in RC circuits
  • Investigate the effects of dielectric materials on capacitance
  • Learn about the implications of capacitance in practical applications, such as in capacitive sensors
USEFUL FOR

Students studying electrical engineering, physics enthusiasts, and professionals working with capacitors and insulating materials will benefit from this discussion.

tarellan
Messages
5
Reaction score
0

Homework Statement



A parallel-plate capacitor has plates of 10 cm^2 area separated by a 0.10mm layer of glass insulation with resistivity rho = 1.2x10^13 omega*m and dielectric constant k= 5.6. Because of the finite resistivity, current can leak through the insulation.

How do I Show that it depends only on the properties of the insulating material and not on its dimensions?

Homework Equations



C= emf(A/d)


The Attempt at a Solution


I found the time constant for this capacitor to discharge through its insulation. T= 590s
 
Physics news on Phys.org
tarellan said:

Homework Statement



A parallel-plate capacitor has plates of 10 cm^2 area separated by a 0.10mm layer of glass insulation with resistivity rho = 1.2x10^13 omega*m and dielectric constant k= 5.6. Because of the finite resistivity, current can leak through the insulation.

How do I Show that it depends only on the properties of the insulating material and not on its dimensions?

Homework Equations



C= emf(A/d)


The Attempt at a Solution


I found the time constant for this capacitor to discharge through its insulation. T= 590s

Consider the resistivity

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/resis.html#c2

Consider too the equation you have for capacitance.

Notice anything about how - when you combine the 2 - the RC has a tendency not to be dependent on the cross sectional area?
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
2K
Replies
2
Views
1K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
3
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
9
Views
3K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
Replies
1
Views
2K