I’ve been long bothered by the plot device of tossing a hair dryer or other electric appliance into a bathtub to off an unwanted person. It seems to me that a) the first result would be for the device to short out and pop a breaker, or, failing that, b) there couldn’t be a circuit through the putative victim’s body unless the p.v. grabbed the dryer with one hand and the plumbing with the other. Any better ideas?
Fresh water really is not a terribly good conductor. I suppose if there was enough stuff in the water to conduct, (is soap conductive?) you could make a circuit using the pipes as ground (since the water touches the pipes.)
Would you seriously like to be the guinea pig to confirm your theory, John Urban?
It would seem to me that the only guarantee of safety against this scenario is to have an earth leakage circuit breaker installed in the circuit, so that the current can be switched out in half a cycle - before it has time to do any damage to you.
If water was not such a danger, why is it that we go to extraordinary lenghts to ensure that electrical circuits are isolated from moisture where possible? It doesn’t really matter whether water is a relatively poor conductor. The point is that it does conduct electricity, and by having a reasonable current behind the supply, the resistance can be overcome.
In newer houses and apartments, special devices are built into outlets in bathrooms so the power would cut off before the person was electrocuted (this is above and beyond the regular circuit breakers).
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- If you’re in the bathtub and a plugged-in hair dryer falls in, you likely won’t feel it or be affected at all, aside from not being able to use it to do your hair. This was discussed in another thread some time back; that the electricity has to be forced to travel through your body. This is the case only when you try to lift the wet hair dryer OUT of the water while you’re still standing in it, assuming that the hair dryer has gotten wet inside and out and the circuit breaker hasn’t already tripped - then the only way for the electricity to reach ground is to travel through your body. --This all also assumes you don’t touch anything metal, such as the drain or the faucet. The electricity will just flow through the water to the metal drain until it shorts out. If you have a bad ticker it would be dicey, but I would be willing to bet that standing in the opposite end of the tub you wouldn’t even feel anything at all. - MC
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Doesn’t voltage more rightly describe the tendency of electricity to flow in a region of high resistance?
Yes. I this case, the voltage is fixed (120V or 220V AC depending on what country you’re bathing in), the water resistance is fixed (simplifying things a little), and the current depends on those two (V=IR, so I = V/R). You’ll get twice as much current at 220V, in England, as you would in the US. In either case, hopefully, the GFCI would trip first.
Arjuna34
Arjuna34