How does electricity hurt people?

Answer 1

Electricity can be harmful in a couple of ways. If you are to mess with an outlet, it is possible that it could shock you, which would hurt, and leaving the electricity on all the time is also harmful to the environment.

Answer 2

If electric current is passing through your body it means you are being part of a circuit. The current is measured as source voltage divided by the resistance in your body. This means that higher voltage equals a higher current/electrons passing through the body. When you touch a 1.5 volt battery with capability of 9 amperes, you wont feel anything, but if touching a 230 volt power outlet (with cap. of 10 amps) you will be heavily shocked, and are in danger of being killed.

When your body gets a high current through it the resistivity or friction creates heat that will burn your flesh. This is the same for AC or DC. But the AC current is more dangerous because the polarity shift frequency of 50-60 Hz. This will override the sinus-signal to your heart, and it will try to beat 50-60 times a second!!

In a electrical fence such as those used for keeping animals in, the voltage is sometimes over 20000 volts (20kV). Now this is not dangerous to touch, even if you feel it very well, because the energy source is restricted to giving out only a tiny amount of electrons with its high voltage. Volt*amps=energy as watts, and the energy will be microscopic in such a fence.

On a 230 volt AC circuit your body is in danger when the current passes 30 ma (milli-amps) and therefor in a IT-grid (internal terra), every fuse is supplied with a extra switch that cuts when the current going to the neutral point passes 30 ma.

This is not needed in a TN-grid (terra neutral) because it uses a common neutral point, making the first ground/n-point-fault the same as a short circuit, making the fuse switch current off.