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

The resistance of the skin is 98 kΩ

Step-by-step explanation:

Given :

Resistivity
`\rho = 1 * 10^(6)` Ωm

Thickness
`t = 1.5 * 10^(-3)` m

The resistance of skin,

`R = (\rho t)/(A)`

We assume radius of worker palm,

`r = 7 * 10^(-2)` m

Area of worker palm,

`A = \pi r^(2)`

`A = 3.14 * 49 * 10^(-4)`

`A = 1.53 * 10^(-2)`
`m^(2)`

So the resistance of palm is,

`R = (10^(6) * 1.5 * 10^(-3) )/(1.53 * 10^(-2) )`

`R = 98 * 10^(3)` Ω

Therefore, the resistance of the skin is 98 kΩ