The resistance of the body varies from approximately 500 kΩ (when it is very dry) to about 1.20 kΩ (when it is wet). The maximum safe current is about 4.90 mA. At 10.0 mA or above, muscle contractions can occur that may be fatal.
(a) What is the largest potential difference that a person can safely touch if his body is wet?
(b) Is this result within the range of common household voltages?

a) The maximum potential difference the wet human body can take = 5.88 V

b) This value is very much lower than the normal voltage of household outlets (120 V) and isn't in the same range at all.

This means one should be very careful operating electrical appliances (even at home) while the body is wet.

Explanation:

From Ohm's law, V = IR

The resistance of the body when the body is wet = 1.2 kΩ = 1200 Ω

Maximum safe current that the body can withstand = 4.90 mA = 0.0049 A

Maximum voltage the body can withstand while wet = (Maximum safe current that the body can withstand) × (Resistance of the body when the body is wet) = 0.0049 × 1200 = 5.88 V

b) This value is still very much lower than the normal voltage of household outlets (120 V) and isn't in the same range at all.

This means one should be very careful operating electrical appliances (even at home) while the body is wet.

Explanation:

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