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Paul Burridge wrote in message . ..
The power company run a line to my house. They supply me with electricity. This amounts to a 230V, 65A facility at the distribution board in a cupboard under the stairs. I run all my stuff from that board. The board contains several RCBOs that trip-out in the event of any leakage current being sensed. If current in = current out; they're happy and won't trip. Because they don't trip out, I conclude I don't use any current. Two things flow along wires: charge and energy. The energy flows fast, while the charges flow slowly. The charges flow in a complete circle (you don't use any up,) while the energy is absorbed by your appliances. OK, here's the big question: which one is the electricity? If an electric current is a flow of electricity, then "electricity" is not energy, and the utility companies neither produce nor sell any electricity. It all depends on how we define the word "electricity." And unfortunately the reference books don't agree with each other. Some books follow the scientists of old, and define electricity as charge (so a quantity of electricity is measured in coulombs, and a flow of electricity is measured in amperes.) Other reference books ignore that definition, and instead they insist that electricity is energy... so a flow of electricity is measured in watts, not amps. The voltage supplied is 230VAC RMS. Since this is alternating between equal positive and negative half-cycles, the average level of this voltage supply is zero. I use no current and they effectively supply no voltage. Why do I get billed for electricity usage when I clearly can't have used any? The path for electric current is CIRCULAR. For every bit of charge that the electric companies force into your appliances, an equal amount of charge goes back out through the other wire. The current is also oscillating (the charges don't actually flow, instead they vibrate back and forth over extremely tiny distances.) On the other hand, the path for electrical energy is one way. The electric companies send electromagnetic energy over enormous distances. It's this energy which your appliances consume. Unfortunately for our definition of "electricity," this energy is composed of electric and magnetic fields, and it travels in the space surrounding the wires. Do we really want to state that electricity is made of EM fields? Do we really want to say that no electricity travels inside of wires, but instead it travels in the space outside? If we say that electricity is a form of energy, that's the same as saying that electricity is just some travelling waves of electromagnetic field. Possible solution: never use the word electricity at all. If you want to say that electrical energy flows along a circuit, then say exactly that. If you want to talk about flows of charge, then speak of charge and not "electricity." As long as we never mention the word "electricity," then amperes and watts are no longer mistaken for each other, and we can get on with explaining the joules and coulombs in ways that make sense. |