Originally Posted by BigMac2
Originally Posted by Vadania
Ummm. It doesn't matter what the voltage is. It's the current (Amperage) that usually causes fatalities. A common personal GGCI is rated to trip at 10ma because 20ma is enough to cause fibrillation which can result in death. It has nothing to do with the part being a "cheap knockoff" if the conditions were right.
The human body can actually withstand Kilovolts of electricity as long as the amperage and conditions are optimal.
My favorite job.
Ummm, Voltage, amperage and resistance does matter. Amperage or voltage alone doesn't mean anything. At 5 volts you need a lots of amperages (something like a million amp) to kill someone. I bet the USB cable will burn way before enough currant can go thru and kill someone.
Where on earth did you get those bizarre ideas from? It is purely current that determines lethality (although in any given system the applied voltage determines the current), and the threshold is around 50 mA but, that aside, your suggested scenario is amusing enough to explore as a thought experiment. Ignoring other breakdown effects, to drive 1 MA through a body with a resistance of at least 1 kΩ would require a voltage of 1 GV (10⁹ V), with a corresponding power dissipation (I²R) of 1 PW (10¹⁵ W). Using the heat capacity and latent heat of vaporization of a 70 kg human yields the result, at that power level, that the unfortunate subject would be entirely vaporized in approximately 0.2 microseconds. So yes - that would be fatal.
It is, of course, completely impossible, with any existing power source (either natural or artificial), to drive 1 MA into a resistive load of that kind. We certainly can drive even 10s of MA, but only into extemely low impedance systems.