My Cap Runneth Over

A Place For Everything

In part 1 we learned about basic electricity, including voltage, current, resistance, and power. We learned that there are lots and lots of tiny little electrons willing to give all their energy every day, getting up and going off to work. They do work for us, saving only enough energy to get back home. All they require is a bit of motivation (electromotive force, voltage) and a path to get back home. They can't do their work if the factory is too crowded with tired electrons.

But what if we gave those electrons a break room? A gathering place where they could rest while waiting to do their work. Think of a factory that starts work at 7 AM. At maybe 6:30 workers will start coming in. But they can't really do any work until everyone gets there and the machinery is started up. Until then they will gather in the break room, sipping coffee and telling wild stories of their adventures the previous night. At first there is no one in the break room. Then one or two people, then more and more until the room is full. No work gets done in the break room, but with those workers present there is the potential to do work. The more workers present, the more potential there is for work.

When the machines start up and the whistle blows, all the workers go out to the assembly line at once and work together. They are able to get more work done in a hurry than if they all came in one by one, did their work, and went home. The break room acts as a sort of storage device for energy, or potential work.

We can create a break room for electrons and it can be quite useful. And here again those imaginative physicists came up with some really creative names. Since our electron break room has the capacity to hold electrons, they named it "capacitance." Wow! How did physicists get the reputation of being dull and boring? They also needed some unit to measure the capacitance. As usual, they chose a dead physicist, Michael Faraday, and called the units Farads. Faraday was quite the intersting and prolific chap. He was one of three people, along with Isaac Newton and James Clerk Maxwell, who Albert Einstein honored by hanging their photos on his wall. That's some pretty weighty company.

the break romm doesnt fill at the same rate. the fuller it gets the slower it fills