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I take no responsibility if you injure or kill your self reading this. DO NOT play with electricity.
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First, you are throwing around the lethal current values like it's a football. The exact value depends on many factors, but generaly 100mA will be lethal.
But what will make that current flow? A car battery will happily put out 50A if you put a wire accross its poles (until it catches fire), but if you touch it you will not go up in flames. How come a source capable of producing 50A currents is not killing you? It's our old friend voltage.
A wire has low resistance, so it will let high currents pass even at low voltage (usually 12V with a car battery). Human body has high resistance (1000-100.000 Ohms, again depending on conditions) so you need more force (ie. higher voltage) if you want to push current thru it. Generally, a value of 50V is taken as enough. If your skin is really dry that day, even 100V may leave you standing. In extreme cases, with people who have an illness that prevents their sweat glands from working can handle even higher voltages. Example
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Now let's take a cigarette ligher, the one that makes a little ark to light the flame. This ark will be 10000V+ but will not kill you. Why? The little magnet inside can't produce high currents. The maximum current it can produce is so low that even if the voltage has no problems going thru your skin, it will do you no harm.
Note the maximum current thing. Even if a source is capable of producing high current, the actual current passing thru you is limited by your body's resistance and the source voltage.
Low voltage, low max amps = Ok
Low voltage, high max amps = Ok
High voltage, low max amps = Ok
High voltage, high max amps = not ok