Dielectric Filled Parallel Plate Capacitor Question

AI Thread Summary
A parallel plate capacitor with mylar dielectric requires calculating the thickness of the dielectric to prevent electrical breakdown at 1600 V. The user is struggling to set up the problem without knowing the charge (Q) and is advised to use the electric field equations, including E(through dielectric) = E0/κ. The total voltage across the dielectric and the gap must equal the maximum voltage. Additionally, looking up the dielectric strength of mylar is suggested as a shortcut to determine the minimum thickness needed. Understanding the calculations for dielectric thickness is essential for accurate problem-solving.
SabreV45
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Homework Statement


A parallel plate capacitor has rectangular plates measuring 44.0 cm by 30.0 cm, and can be charged to 1600 V maximum ΔV without electrical breakdown. The gap between the plates is fulled with mylar dielectric (κ=3.2). Find the thickness of the dielectric.

Homework Equations



C=κC0
C=Q/ΔV
C00(A/d)

The Attempt at a Solution



I believe I am missing an equation needed to solve this question. The way I had this question set up, I wasn't able to solve without a value for Q.
 
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SabreV45 said:

Homework Statement


A parallel plate capacitor has rectangular plates measuring 44.0 cm by 30.0 cm, and can be charged to 1600 V maximum ΔV without electrical breakdown. The gap between the plates is fulled with mylar dielectric (κ=3.2). Find the thickness of the dielectric.


Homework Equations



C=κC0
C=Q/ΔV
C00(A/d)


The Attempt at a Solution



I believe I am missing an equation needed to solve this question. The way I had this question set up, I wasn't able to solve without a value for Q.

The voltage across the dielectric + the voltage across the gap = your total voltage.

Remember in a constant field, voltage is just given as E*d.
And the equation you're missing is :

E(through dielectric) = E0/κ , with E0 the field between the plates without any dielectric.
 
Apphysicist said:
The voltage across the dielectric + the voltage across the gap = your total voltage.

Remember in a constant field, voltage is just given as E*d.
And the equation you're missing is :

E(through dielectric) = E0/κ , with E0 the field between the plates without any dielectric.

Thanks for the info. I'm still not exactly sure how to solve for the thickness of the dielectric.

I'm mainly having problems setting up with question, once I get it set up I'll be able to solve everything myself. I'm just not able to think of a way to solve this question without having the value for Q.
 
Cheat. Look up the dielectric strength for mylar and determine the minimum thickness for 1600V breakdown. :smile:
 
gneill said:
Cheat. Look up the dielectric strength for mylar and determine the minimum thickness for 1600V breakdown. :smile:

I would prefer to be able to understand the calculations needed to determine the thickness of the dielectric. This was a question that I got wrong on a test and am trying to solve them correctly to keep in my records.
 
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