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# Why does a fully charged capacitor have a potential difference? watch

1. When a capacitor is fully charged there is no current in the circuit. So since V=IR, and there is 0 current (I) surely the potential difference should be 0 also?
Also, if potential difference is the energy transferred from the circuit to the surroundings per unit of charge. What is the energy being transferred to in a circuit with a fully charged capacitor?
2. (Original post by FarmerMan)
When a capacitor is fully charged there is no current in the circuit. So since V=IR, and there is 0 current (I) surely the potential difference should be 0 also?
Also, if potential difference is the energy transferred from the circuit to the surroundings per unit of charge. What is the energy being transferred to in a circuit with a fully charged capacitor?
that's ohm's law the equation for current flowing in a resistance, But pd can exist without a current; static electricity, if charged particles have previously been pushed into different concentrations on the 2 plates and then are left sitting there.
3. (Original post by FarmerMan)
When a capacitor is fully charged there is no current in the circuit. So since V=IR, and there is 0 current (I) surely the potential difference should be 0 also?
Also, if potential difference is the energy transferred from the circuit to the surroundings per unit of charge. What is the energy being transferred to in a circuit with a fully charged capacitor?
Think of potential difference as an analogy to water pressure provided by a tank (capacitor) some height off the ground and water flowing in a pipe is the current.

Then a current can fill the tank and be shut off, but the water still remains in the tank and provides a pressure which only flows as a current again when the circuit is completed.

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