Confused on this dielectric capacitance problem

In summary, to determine the capacitance of a paper-separated capacitor with a voltage of 9.41E4 V/m and charge of 0.775E-6C on each plate, first use the equation V = Ed to calculate the voltage. Then, use E = \frac{Q}{\epsilon_0A} to find the area of each plate, which can be used to calculate the capacitance using the equation C=Q/V. This equation applies for dielectrics as well.
  • #1
supermenscher
47
0
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?
 
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  • #2
I think you should be able to use the fact that [itex]E = \frac{Q}{\epsilon_0A}[/itex]. This gives you an equation for the area which you can use to determine the capacitance.
 
  • #3
I tried that and that did not work out either, do you have anymore suggestions?
 
  • #4
supermenscher said:
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.
 

1. What is dielectric capacitance?

Dielectric capacitance is a measure of a material's ability to store electrical energy when placed between two conductors. It is denoted by the symbol C and is measured in farads (F).

2. How is dielectric capacitance calculated?

Dielectric capacitance is calculated using the formula C = εA/d, where ε is the permittivity of the material, A is the area of overlap between the two conductors, and d is the distance between them.

3. What is the role of dielectric materials in capacitors?

Dielectric materials are used in capacitors to increase their capacitance. This is because these materials have a high permittivity, which allows for more electric field lines to be established between the conductors, thus increasing the overall capacitance.

4. How does the dielectric constant affect capacitance?

The dielectric constant, also known as the relative permittivity, is a measure of how well a material can store electrical energy. A higher dielectric constant means that the material has a higher capacitance, as it can store more electrical energy.

5. Can the dielectric material affect the capacitance of a capacitor?

Yes, the type of dielectric material used in a capacitor can significantly affect its capacitance. Materials with higher permittivity, such as ceramic or polyester, will have a higher capacitance compared to materials with lower permittivity, such as air or vacuum.

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