The resistance of a square centimeter of dry human epidermis is about 1.6 times

Question

The resistance of a square centimeter of dry human epidermis is about 1.6 times 105 Ohm. Suppose that a (foolish) man firmly grasps two wires in his fists. The wires have a radius of 0.12cm, and the skin of each hand is in full contact with the surface of the wire over a hand is in full contact with the surface of the wire over a length of 8.0 cm. Calculate the resistance the man offers to a current flowing through his body from one wire to the other. In this calculation you can neglect the resistance of the internal tissues of the human body, because the body fluids are reasonably good conductors and their resistance is small compared with the skin resistance. Contact between hand and wire. Req = What current will flow through the body of the man if the potential difference between the wires is 15 V? I =

Explanation / Answer

Resistance per square cm gives the value of resistivity()

So, using R=l/A, where l=8cm=0.08 m; A=r2 =4.52X10-6 sq.m

R=2.83X 109

Using Ohm's law, V=IR,

so I=V/R=5.83 X 10-9 A = 0.00583 A

This amount of current is harmless.

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