Most of the resistance of the human body comes from the skin, asthe interior of the body
Question:
Most of the resistance of the human body comes from the skin, asthe interior of the body contains aqueous solutions that are goodelectrical conductors. For dry skin, the resistance between aperson's hands is measured at typically 500 k?. The skinvaries in thickness, but on the average it is about 2.0mm thick. We can model the body between the hands as acylinder 1.6 m long and 14 cmin diameter with theskin wrapped around it.
(a) What is the resistivity of the skin?
Ω · m
(b) Compare your answer with the internal resistivity of the body, approximately
4.8 Ω · m.
ρskin |
ρinterior |
=
How do you explain the fact that the resistance of the skin is about 1000 times greater than the internal resistance of the body, even though the resistivity of the skin is only about 60times that of the interior of the body?
A )The skin has a smaller cross sectional area.
B )The resistance of an object scales exponentially with respectto the resistivity of the material out of which it ismade.
C ) The skin is constantly moistened by biologicalprocesses.
D ) Charges can only exist on the surface of conductors.
Fundamentals Of Momentum Heat And Mass Transfer
ISBN: 9781118947463
6th Edition
Authors: James Welty, Gregory L. Rorrer, David G. Foster