Question

Most of the resistance of the human body comes from the skin, as the interior of the body contains aqueous solutions that are good electrical conductors. For dry skin, the resistance between a person’s hands is typically 500 kΩ. The skin is on average about 2.0 mm thick. We can model the body between the hands as a cylinder 1.6 m long and 14 cm in diameter with the skin wrapped around it. What is the resistivity of the skin?

Answer 1

Answer:

4.81x10³ Ω*m

Explanation:

The resistivity (ρ) of the skin can be calculated using the following equation:

$\rho = R\frac{A}{l}$

Where:

R: is the electrical resistance of the skin = 500x10³ Ω

A: is the cross-sectional area of the skin

l: is the length of the skin= 1.6 m

Since we can model the body between the hands as a cylinder, the cross-sectional area is:

$A = \pi r^{2} = \pi \frac{d^{2}}{4} = \pi \frac{(0.14 m)^{2}}{4} = 1.54 \cdot 10^{-2} m^{2}$

Now, we can fin the  resistivity (ρ) of the skin:

$\rho = R\frac{A}{l} = 500\cdot 10^{3} \Omega \frac{1.54 \cdot 10^{-2} m^{2}}{1.6 m} = 4.81 \cdot 10^{3} \Omega m$  

Therefore, the resistivity of the skin is 4.81x10³ Ω*m  

I hope it helps you!