The damage caused by electric shock depends on the current flowing through the b

Question

The damage caused by electric shock depends on the current flowing through the
body; 1 mA can be felt and 5 mA is painful. Above 15 mA, a person loses muscle control, and 70 mA can be fatal. A person with dry skin has a resistance from one arm to the other of about 130000 . When skin is wet, the resistance drops to about 5400 .
(a) What is the minimum voltage placed across the arms that would produce a current that could be felt by a person with dry skin? Answer in units of V.
(b) Using the same electric potential as in Part 1, what would be the current if the person had wet skin? Answer in units of mA.
(c) What would be the minimum voltage that would produce a current that could be felt when the skin is wet? Answer in units of V.

Explanation / Answer

For all these questions, we can use Ohm's Law which is V = iR V = Potential Difference (Voltage) i = Current (1 mA = 1 x 10^-3 A) R = Resistance (a) V = iR = (1 x 10^-3 A)(130000 ohms) = 130 V (b) V = iR i = V/R = (130 V)/(5400 ohms) = 0.0241 A = 24.1 mA (c) V = iR = (1 x 10^-3)(5400 ohms) = 5.4 V

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.