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- PHY102 Physics II © Dr.Cem Özdoğan
- 25-2 Charging a Capacitor
- When a circuit with a battery, an open switch, and an uncharged capacitor is completed by closing the switch, conduction electrons shift, leaving the capacitor plates with opposite charges.
- In Fig. a, a battery B, a switch S, an uncharged capacitor C, and interconnecting wires form a circuit.
- The same circuit is shown in the schematic diagram of Fig. b, in which the symbols for a battery, a switch, and a capacitor represent those devices.
- The battery maintains potential difference V between its terminals.
- The terminal of higher potential is labeled + and is often called the positive terminal; the terminal of lower potential is labeled - and is often called the negative terminal.
- When the switch is closed, electrically connecting those wires, the circuit is complete and charge can then flow through the switch and the wires.
- As the plates become oppositely charged, that potential difference increases until it equals the potential difference V between the terminals of the battery.
- The capacitor is then said to be fully charged, with a potential difference V and charge q.