Question

The relatively high resistivity of dry skin, about 1×106Ω⋅m, can safely limit the flow of current into deeper tissues of the body. Suppose an electrical worker places his palm on an instrument whose metal case is accidently connected to a high voltage. The skin of the palm is about 1.5 mm thick.

Answer 1

Answer:

The resistance of the skin is 98 kΩ

Explanation:

Given :

Resistivity $\rho = 1 \times 10^{6}$ Ωm

Thickness $t = 1.5 \times 10^{-3}$ m

The resistance of skin,

  $R = \frac{\rho t}{A}$

We assume radius of worker palm,

$r = 7 \times 10^{-2}$ m

Area of worker palm,

 $A = \pi r^{2}$

 $A = 3.14 \times 49 \times 10^{-4}$

 $A = 1.53 \times 10^{-2}$ $m^{2}$

So the resistance of palm is,

$R = \frac{10^{6} \times 1.5 \times 10^{-3} }{1.53 \times 10^{-2} }$

$R = 98 \times 10^{3}$ Ω

Therefore, the resistance of the skin is 98 kΩ