Skin and Current
Name: Deniz D.
How does the resistance of skin differ under AC and DC
The resistance does not differ significantly under AC vs DC conditions.
What differs is the time over which current flows in one direction or the
other. DC current flows steadily in one direction. AC current oscillates
back and forth sixty times per second.
For DC current, the body can counter effects for only a fraction of a
second. Within a very short time, 10 to 12 volts may be enough to interrupt
electrical signals within your body (brain, heart, ...). The AC current
oscillates so fast that your body is better able to deal with it. Greater
voltage is necessary to interrupt your body. For only 10-15 Volts, you have
a little time to pull away from the electric source. Still, the 120V of a
standard outlet provides enough current that the oscillations won't save you
Dr. Ken Mellendorf
Illinois Central College
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Update: June 2012