The relatively high résistivité of dry skin can safely limit the flow of current into deeper tissues
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Resistivity is a measure of how strongly a material opposes the flow of electric current. Dry skin has a relatively high resistivity compared to other tissues in the body. Show more…
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Current in the body. The resistance of the body varies from approximately 500 $\mathrm{k} \Omega$ (when it is very dry) to about 1 $\mathrm{k} \Omega$ (when it is wet). The maximum safe current is about 5.0 $\mathrm{mA} .$ At 10 $\mathrm{mA}$ or above, muscle contractions can occur that may be fatal. What is the largest potential difference that a person can safely touch if his body is wet? Is this result within the range of common household voltages?
In the conduction equation $Q=(k A \Delta T) t / L,$ the combination of terms $k A / L$ is called the conductance. The human body has the ability to vary the conductance of the tissue beneath the skin by means of vasoconstriction and vasodilation, in which the flow of blood to the veins and capillaries is decreased and increased, respectively. The conductance can be adjusted over a range such that the tissue beneath the skin is equivalent to a thickness of $0.080 \mathrm{mm}$ of Styrofoam or $3.5 \mathrm{mm}$ of air. By what factor (high/low) can the body adjust the conductance?
The resistance of the body varies from approximately 500 kΩ (when it is very dry) to about 0.900 kΩ (when it is wet). The maximum safe current is about 5.30 mA . At 10.0 mA or above, muscle contractions can occur that may be fatal. 1.) What is the largest potential difference that a person can safely touch if his body is wet? Express your answer in Volts using two significant figures. 2.) Is this result within the range of common household voltages? (Yes or No)
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