Pulling apart a charged capacitor and Poynting theorem.

In summary, when we have equal and opposite charge densities on a parallel plate capacitor and we slowly separate the plates, the electrostatic field energy approximately doubles. This doubling can be accounted for by carefully applying Poynting's theorem to the problem.
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Spinnor
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Suppose we have equal and opposite charge densities on a parallel plate capacitor. Let the plates be separated some small distance d (small when compared with the plate size). Now slowly separate the plates so that their separation is now doubled to 2d. We have done work and the electrostatic field energy has roughly doubled. Should a careful application of Poynting's theorem to this problem account for the doubling of electrostatic energy?

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Spinnor said:
We have done work and the electrostatic field energy has roughly doubled. Should a careful application of Poynting's theorem to this problem account for the doubling of electrostatic energy?
Yes.
 
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Related to Pulling apart a charged capacitor and Poynting theorem.

1. What is a charged capacitor?

A charged capacitor is an electronic component that stores electrical energy in the form of electric charge. It consists of two conductive plates separated by an insulating material, or dielectric, and is commonly used in electronic circuits to regulate and store electrical energy.

2. How does a capacitor store energy?

When a capacitor is connected to a power source, it becomes charged as one plate accumulates positive charge and the other accumulates negative charge. This creates an electric field between the plates, which stores energy in the form of potential energy. The capacitor can then release this energy when connected to a circuit, allowing the charges to flow from one plate to the other.

3. What happens when a charged capacitor is pulled apart?

When a charged capacitor is pulled apart, the electric field between the plates is disrupted and the energy stored in the capacitor is released. This can result in a spark or discharge between the plates as the charges try to equalize.

4. What is Poynting theorem?

Poynting theorem is a fundamental law in electromagnetism that describes the flow of energy in an electromagnetic field. It states that the rate of change of energy in a given volume of space is equal to the negative of the divergence of the Poynting vector, which represents the direction and magnitude of energy flow.

5. How is Poynting theorem related to a charged capacitor?

Poynting theorem is applicable to any electromagnetic system, including a charged capacitor. In the case of a capacitor, the Poynting vector describes the flow of energy between the plates as the capacitor charges and discharges. Poynting theorem can be used to calculate the energy stored in a capacitor and the rate at which it is released.

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