Difference in the maximum potential capacitance

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Homework Help Overview

The discussion revolves around calculating the capacitance and the maximum potential difference for a parallel plate capacitor filled with Teflon. The problem involves parameters such as the dielectric constant, plate area, and plate separation.

Discussion Character

  • Exploratory, Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants explore the calculation of capacitance and the potential difference, with some expressing confusion about the necessary formulas and variables, particularly the dielectric strength and electric field.

Discussion Status

There is ongoing exploration of the relationship between voltage, dielectric strength, and plate separation. Some participants have provided guidance on relevant formulas, while others are questioning the availability of certain values needed for calculations.

Contextual Notes

Participants note the absence of the dielectric strength value and discuss its relevance to the problem. The original poster has provided some calculations but seeks further clarification on the potential difference aspect.

Apprentice123
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Determine (a) capacitance and (b) the difference in the maximum potential that can be applied to a parallel plate capacitor filled with Teflon (k=2,1), whose area the plate is 1,75 cm^2 and the separation between the plates is 40x10^{-6}m.


My solution

(a) C. = ( E. * A )/d = 3,87x10^{-12}F
C = k * C. = 8,127x10^{-12}F

(b) not understand
 
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Apprentice123 said:
potential difference of

V = (Q*d)/(E.*A)

I do not have Q

You don't need Q.

The dielectric strength is only dependent on distance, and that you are given.
 


LowlyPion said:
You don't need Q.

The dielectric strength is only dependent on distance, and that you are given.

I do not know the formula. But what you are saying is that:
V / (Dielectric strength) = separation between plates ?
 


Apprentice123 said:
I do not know the formula. But what you are saying is that:
V / (Dielectric strength) = separation between plates ?

Yes! V=Ed, or V/E=d, for uniform E.
 


ideasrule said:
Yes! V=Ed, or V/E=d, for uniform E.

But I do not have E
 
Last edited:


Apprentice123 said:
But I do not have E

What are the units for dielectric strength?
 


ideasrule said:
What are the units for dielectric strength?

In this problem I have the dielectric constant (no unit). I do not have the dielectric strength
 
  • #10


Apprentice123 said:
In this problem I have the dielectric constant (no unit). I do not have the dielectric strength

The link I gave you earlier has a number for the dielectric strength.

http://en.wikipedia.org/wiki/Dielectric_strength

You know the thickness, so figure the maximum voltage.
 
  • #11


LowlyPion said:
The link I gave you earlier has a number for the dielectric strength.

http://en.wikipedia.org/wiki/Dielectric_strength

You know the thickness, so figure the maximum voltage.

Dielectric Strength = 1,73x10^8

V = 1,73x10^8 * 40x10^{-6} = 6920 V


which symbol to Dielectric strength ?
 
  • #12


Apprentice123 said:
which symbol to Dielectric strength ?

Whatever strikes your fancy.
 

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