PDA

View Full Version : confused on this dielectric capacitance problem


supermenscher
Jun24-04, 02:12 PM
The electric field between the plates of a paper-separated (K=3.75) capacitor is 9.41E4 V/m. The plates are 1.75mm apart and the charge on each plate is 0.775E-6C. Determine the capacitance of the capacitor and the area of each plate?

I got the voltage by V=Ed. and that came out to 164.675

Where do i go from there because in order to get capacitance you need to know area, and finding the area of each plate is also a question in the problem. I thought about using C=Q/V, but that doesn't apply for dielectrics. Can someone helpme out?

e(ho0n3
Jun24-04, 02:58 PM
I think you should be able to use the fact that E = \frac{Q}{\epsilon_0A}. This gives you an equation for the area which you can use to determine the capacitance.

supermenscher
Jun24-04, 03:28 PM
I tried that and that did not work out either, do you have anymore suggestions?

Doc Al
Jun24-04, 06:54 PM
Where do i go from there because in order to get capacitance you need to know area, and finding the area of each plate is also a question in the problem. I thought about using C=Q/V, but that doesn't apply for dielectrics.
Who says that C = Q/V doesn't apply for dielectrics? It's the definition of capacitance.