- #1
Opus_723
- 178
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I'm in Circuit Analysis I this quarter, and I'm having a bit of trouble understanding voltage conceptually.
I understand the water pump analogy. Voltage is analogous to water pressure, etc. I just need to clear up a few things.
My book describes voltage as potential energy. I understand that if you separate protons from electrons, they have potential energy, since there is an attractive force between them. In a battery, the electrons are separated from the protons, and this attractive force makes them pass through the wire in order to come together.
But now I'm wondering how you achieve different voltages. If I separate twice as many charges, I must have used twice as much energy to do so, in which case the energy per coulomb would be the same. At first I thought that changing the distance between the separated charges made sense, but in that case, charges that were barely separated would have a stronger attractive force between them, and thus more voltage. It seems then, that connecting the ends of a battery with a longer wire would result in less voltage. Intuitively, I don't think that happens. Also, the equation V=W/Q doesn't include distance as a factor. I'm just failing to see how you can change the amount of potential energy of a charge, without involving distance. But maybe I'm just stuck thinking of potential energy in terms of balls and gravity from high school.
I don't know if this makes any sense. I'm probably misinterpreting something very fundamental, but I can't seem to get at it by myself. Everything I look up uses terms I don't understand, and I don't know where to begin decoding.
I'd really appreciate some help.
(If this belongs in the EE forum, I apologize, but since this is a such a fundamental concept, I thought Physics would be more appropriate.)
I understand the water pump analogy. Voltage is analogous to water pressure, etc. I just need to clear up a few things.
My book describes voltage as potential energy. I understand that if you separate protons from electrons, they have potential energy, since there is an attractive force between them. In a battery, the electrons are separated from the protons, and this attractive force makes them pass through the wire in order to come together.
But now I'm wondering how you achieve different voltages. If I separate twice as many charges, I must have used twice as much energy to do so, in which case the energy per coulomb would be the same. At first I thought that changing the distance between the separated charges made sense, but in that case, charges that were barely separated would have a stronger attractive force between them, and thus more voltage. It seems then, that connecting the ends of a battery with a longer wire would result in less voltage. Intuitively, I don't think that happens. Also, the equation V=W/Q doesn't include distance as a factor. I'm just failing to see how you can change the amount of potential energy of a charge, without involving distance. But maybe I'm just stuck thinking of potential energy in terms of balls and gravity from high school.
I don't know if this makes any sense. I'm probably misinterpreting something very fundamental, but I can't seem to get at it by myself. Everything I look up uses terms I don't understand, and I don't know where to begin decoding.
I'd really appreciate some help.
(If this belongs in the EE forum, I apologize, but since this is a such a fundamental concept, I thought Physics would be more appropriate.)