Where Does the Energy Go in a Capacitor Without Resistance?

In summary, the conversation discusses the charging of a capacitor by a battery with no resistance. The end charge of the capacitor is equal to the capacitance multiplied by the battery's electromotive force. The work done by the battery is equal to the charge multiplied by the electromotive force, but the energy of the charged capacitor is only half of this value. The question is raised about where the lost energy goes and whether the kinetic energy of the charges should be considered. A forum thread suggests that a model without resistance is not physically accurate and that including resistance resolves the issue.
  • #1
Yegor
147
1
The capacitor of capacitance C is charged by battery (emf = E) (assume that there is no resistance). In the end charge of the capacitor Q = C*E; Work done by the battery W = Q*E=C*E^2. But The energy of charged capacitor is U = (C*E^2)/2. Work doesn't equals to stored energy. Where we lost energy?? Can we forget about kinetic energy of the charges it this case?? Or it is exactly that "lost" energy?
 
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  • #3
Thank you very much. As i understood, the model without resistance isn't really physical. With nonzero resistance everything is ok.
 

FAQ: Where Does the Energy Go in a Capacitor Without Resistance?

What is the energy of a capacitor?

The energy of a capacitor is the amount of work required to charge the capacitor to a specific voltage. It is stored in the electric field between the two plates of the capacitor.

How is the energy of a capacitor calculated?

The energy of a capacitor can be calculated using the formula E = 1/2 * C * V^2, where E is the energy in joules, C is the capacitance in farads, and V is the voltage across the capacitor.

What is the relationship between the energy of a capacitor and its capacitance?

The energy of a capacitor is directly proportional to its capacitance. This means that as the capacitance increases, the energy stored in the capacitor also increases.

How does the energy stored in a capacitor change when the voltage across it is increased?

The energy stored in a capacitor is directly proportional to the square of the voltage across it. This means that as the voltage increases, the energy stored in the capacitor increases exponentially.

What is the work done in charging a capacitor?

The work done in charging a capacitor is equal to the change in energy of the capacitor. This can be calculated using the formula W = E2 - E1, where W is the work done, E1 is the initial energy, and E2 is the final energy of the capacitor.

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