The question aims to find the **resistance** of the **skin** of the **palm** of the **hand** of an **electrical worker** whose hand is accidentally touched on a **high voltage** panel.

The question is based on the concept of **resistance** of any **material.** The **resistance** of any **material** is defined as the **oppositional force** exerted by any material to the **flow** of **current** through that **material.** Its formula is given as:

\[ Resistance\ R = \dfrac{ \rho \times Length }{ Area } \]

Here, $\rho$ is called the **resistivity** of the **material,** which shows how **good** any **material** is in **stopping** the **flow** of **current.**

## Expert Answer

The given information for this problem is given as:

\[ Resistivity\ of\ the\ Skin\ \rho = 1.0 \times 10^6 \Omega . m \]

\[ Thickness\ of\ the\ Skin\ t = 1.5 mm \]

To calculate the **resistivity** of the **skin** of the **hand palm,** we need its **Area.** To calculate the area of the hand, we need the **length** and **breadth** of the **palm** of the **hand** of the **worker.** As such information is not given in the question and there is no other way to determine these **values.** We simply have to assume these values.

Assuming the **length** of the **palm** of the **hand** of an **electrical worker** is equivalent to the **average adult palm,** which is given as:

\[ l = 4 in\ or\ 101.6\ mm \]

Similarly, assuming **average** adult palm **breadth** for the worker which is given as:

\[ b = 3.3 in\ or\ 83.8\ mm \]

The **area** of the **palm** of the **hand** of the electrical worker is given as:

\[ A = l \times b \]

\[ A = 0.101 \times 0.083 \]

\[ A = 0.0084\ m^2 \]

We can now use the formula of the **resistance** to calculate the **resistance** of the **skin** of the** palm,** which is given as:

\[ R = \dfrac{ \rho \times t }{ A } \]

Substituting the values, we get:

\[ R = \dfrac{ 1 \times 10^6 \times 1.5 \times 10^{-3} }{ 0.0084 } \]

\[R = 1.8 \times 10^5 \Omega\]

## Numerical Result

The **area** of the **skin** of the **hand** that contacted the panel is calculated to be:

\[ A = 0.0084\ m^2 \]

The **resistance** of the **skin** of the **hand** is calculated to be:

\[R = 1.8 \times 10^5 \Omega\]

## Example

A worker’s** palm** touched an **electrical panel.** The **area** of the** palm** is $0.01 m^2$. The **resistivity** of the **skin** of the **hand** is $1 \times 10^6 \Omega.m$. Find the **resistance** of the skin if the **skin** is** 1 mm thick**.

Using the **resistance formula** to calculate the resistance as:

\[ R = \dfrac{ 1 \times 10^6 \times 1 \times 10^{-3} }{ 0.01 } \]

\[ R = \dfrac{ 1 \times 10^{ 6 – 3 } }{ 0.01 } \]

\[ R = 1 \times 10^5 \Omega\]

The **resistance** of the **skin** of the **hand** of the **worker** is calculated to be $1 \times 10^5 \Omega$.