Area of a Parallel Plate capacitor. Pi*r^2?

In summary, the formula for the area of a parallel plate capacitor is A = π*r^2, and it can be calculated by multiplying the value of π by the square of the radius of the plates. The area is important because it determines the capacitance and can be changed by adjusting the distance between the plates or changing the size of the plates. The area directly affects the performance of the capacitor by determining its capacitance and energy storage capacity.
  • #1
Specimen
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0
Hi,

I was just going through a question in my Physics textbook today. In calculating the electric field (E=sigma/epsilon0) ... sigma = charge density = q/Area ... they have used the area as pi*r^2, I can't understand why this was done? shouldn't the area of the parallel plate capacitor be length of one electrode * distance between electrodes?

Hope I'm making sense!
 
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  • #2
No, the area that we use here is the area of one of the electrodes (circular in this case, apparently). The charge resides on the electrodes, not in the space between them.
 
  • #3
Hmm, makes sense. Thanks mate!
 

1. What is the formula for the area of a parallel plate capacitor?

The formula for the area of a parallel plate capacitor is A = π*r^2, where A is the area and r is the radius of the plates.

2. How is the area of a parallel plate capacitor calculated?

The area of a parallel plate capacitor can be calculated by multiplying the value of π (pi) by the square of the radius of the plates.

3. Why is the area of a parallel plate capacitor important?

The area of a parallel plate capacitor is important because it determines the capacitance of the capacitor. A larger area means a larger capacitance, which allows the capacitor to store more charge.

4. Can the area of a parallel plate capacitor be changed?

Yes, the area of a parallel plate capacitor can be changed by adjusting the distance between the plates or by changing the size of the plates themselves.

5. How does the area of a parallel plate capacitor affect its performance?

The area of a parallel plate capacitor directly affects its performance by determining its capacitance. A larger area results in a higher capacitance, which allows the capacitor to hold more charge and have a greater energy storage capacity.

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