Parallel plate capacitor problem

Click For Summary

Homework Help Overview

The discussion revolves around a parallel plate capacitor problem involving dielectric materials. Participants are exploring the relationship between capacitance, dielectric strength, and the physical dimensions of the capacitor, specifically the area of the plates and the separation distance.

Discussion Character

  • Conceptual clarification, Mathematical reasoning, Problem interpretation, Assumption checking

Approaches and Questions Raised

  • Participants are attempting to calculate the minimum area of the capacitor plates and questioning how the dielectric strength affects the separation distance. There are discussions about the formulas involved and the implications of the dielectric constant and dielectric strength on the capacitor's design.

Discussion Status

The discussion is active, with participants providing insights into the calculations needed to determine the separation distance and area. Some have suggested specific calculations while others are clarifying the role of dielectric strength in determining the necessary thickness for voltage ratings.

Contextual Notes

There is an emphasis on understanding the constraints imposed by the dielectric strength and the maximum potential difference. Participants are working within the framework of the problem without reaching a final consensus on the calculations.

Apprentice123
Messages
92
Reaction score
0
A parallel plate capacitor is formed using a material whose dielectric constant is 3,00 and whose dielectric strength is 2x10^{8} V/m. The capacitance is 0,25x10^{-6}F and the capacitor must withstand a potential difference maximum of 4000V. Find the minimum area of the plates of the capacitor

I have

C = (E. * A * k)/d

How to calculate d ?
 
Physics news on Phys.org


Apprentice123 said:
A parallel plate capacitor is formed using a material whose dielectric constant is 3,00 and whose dielectric strength is 2x10^{8} V/m. The capacitance is 0,25x10^{-6}F and the capacitor must withstand a potential difference maximum of 4000V. Find the minimum area of the plates of the capacitor

I have

C = (E. * A * k)/d

How to calculate d ?

How will the dielectric strength constrain the distance separation?

Then solve for A.
 


LowlyPion said:
How will the dielectric strength constrain the distance separation?

Then solve for A.

the dielectric strength (2x10^8 V/m) is the separation of the plates?
 


Apprentice123 said:
the dielectric strength (2x10^8 V/m) is the separation of the plates?

No. That's a property of the material if it was 1 meter thick.

How thick does it need to be to yield a 4000 V rating?
 


LowlyPion said:
No. That's a property of the material if it was 1 meter thick.

How thick does it need to be to yield a 4000 V rating?


V = (q*d)/(E.*A*k)

It is related to d and A again
 


d = 4000 / 2x10^8 = 2x10^{-5}

A = (C*d)/(E.*k) = 1,88x10^{-7}

It is ?
 


Apprentice123 said:
V = (q*d)/(E.*A*k)

It is related to d and A again

Like I said, find d.

For this problem minimum d is the thickness required to provide a 4000 V separation between the plates. That means that with a dielectric strength of 2*108 you need a thickness of 4000/2*108 2*10-5 m.

Then apply that to Area calculation.

Edit: I see you have in your next post. So yes. That looks like the right way to do it.
 


LowlyPion said:
Like I said, find d.

For this problem minimum d is the thickness required to provide a 4000 V separation between the plates. That means that with a dielectric strength of 2*108 you need a thickness of 4000/2*108 2*10-5 m.

Then apply that to Area calculation.

Edit: I see you have in your next post. So yes. That looks like the right way to do it.

Thank you very much!
 

Similar threads

  • · Replies 18 ·
Replies
18
Views
3K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
Replies
3
Views
2K
Replies
5
Views
1K
  • · Replies 20 ·
Replies
20
Views
4K
Replies
4
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
5
Views
2K
  • · Replies 28 ·
Replies
28
Views
3K