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# Befuddled by Electricity watch

1. I seem to have many basic misconceptions concerning electricity. For now I would like to just ask how being electrocuted works. I was gullible enough to fall for a prank by my physics teacher involving a capacitor very much like this:

I touched one plate and there was NO SHOCK. Say it was the positive plate. By my patchy logic shouldn't charge flow through me, and into the metal plate, because there is a charge separation between me and the plate? And additionally, does charge separation mean potential difference?

However, when i touched both plates at once, I was very much shocked. How come charge flowed through me this time and not before?
Also I have failed to grasp where the electrons go. Do a substantial amount flow through me into the floor to earth, or do they move entirely through me from the negative terminal to the positive terminal?
2. Yes I think it's because you're earthed when touching only one plate, so the electricity reduces to 0 voltage, but when touching two the electricity conducts through you at full voltage because electricity needs less energy to pass between two similar voltage levels than to go right to 0. And that is why lightning only happens when there is a powerful enough electrical field rumbling away in the sky that it can overcome the huge voltage difference between it and the ground.

I would imagine with the single plate the electrons all flow through you and are dissipated into the earth because you've only given them one option, while in the second one a (much) larger amount take the easy route to the second plate without losing potential difference and a proportionally (much) smaller amount take the difficult earth route.

But I haven't done this since about 2006 so we will let someone more knowledgeable come along. Just want to see if I'm remembering right really!
3. Thank you for replying. So why then can someone who is earthed be electrocuted by the third rail, or overhead cable if they are earthed, but not when I touch a charged plate?
4. (Original post by awkwardshortguy)
Thank you for replying. So why then can someone who is earthed be electrocuted by the third rail, or overhead cable if they are earthed, but not when I touch a charged plate?
My guess is that the third rail will use you as a medium to send electricity into the ground.. It will be a continuous stream at high voltage!
5. Bump. Still can't understand it. Why do you need to touch both terminals to get a shock but only one third rail or overhead cable?

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Updated: February 12, 2014
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