How Everything Works
How Everything Works How Everything Works

Question 876

If voltage shocks you, why does current kill you?
Your skin is a very good electric insulator and it prevents any current from passing through your body as long as that current doesn't have much voltage. A higher voltage (the electric equivalent of "pressure") is required to push charge through your skin. But once the charge is inside you body, it moves through you quite easily—your body fluids are essentially salt solutions and are relatively good conductors of electricity.

However, a small current passing through your body won't cause injury. It takes about 0.030 amperes or 30 milliamperes to cause a life-threatening disturbance to your "electric system." The small currents associated with static electricity are not enough to cause trouble, even through they easily pass through your skin. So high voltages are needed to break through your protective barrier—your skin—in order to give you a shock, but large currents are needed to injury you.


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