[Physics] Charging a capacitor (terminals)

capacitancechargeconventionselectrostatics

When a battery is connected to a conductor electrons are repelled from the end of the conductor connected to the negative terminal of the battery and flow to the end of the conductor connected to the positive terminal of the battery, and so on. This can be summarized by saying:

Electrons flow from the negative terminal of the battery to the positive terminal.

However, when charging a capacitor it says:

Electrons flow onto the plate connected to the negative terminal of the battery.

In view of what I said above about electrons flowing from negative terminal to positive, shouldn't it say:

Electrons flow onto the plate connected to the positive terminal of the battery?

Best Answer

Electrons flow through the wire from the battery's negative terminal to the battery's positive terminal. If said wire is actually a capacitor, the electrons still flow the same way - from the battery's negative terminal. But since it's a capacitor, the electrons are pushed into the capacitor's negative plate instead of making it all the way to the battery's positive terminal.

Imagine a battery with a wire connected terminal to terminal as a big circular racetrack. The cars driving around are electrons. Current will keep flowing in a circle... until someone puts a roadblock (a capacitor) on the track. The cars keep circling, but will eventually all pile up on the one side of the roadblock, just as electrons will pile into the negative terminal of the capacitor.

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