Home › ASVAB › Physics › Electric Current, Resistance, and Ohm's Law › A technician standing on a rubber mat has a tota…
A technician standing on a rubber mat has a total resistance of 300 kilohms. What current flows if the technician touches a 120-V AC source?
A4.00 mA
B0.400 mA
C40.0 mA
D2.50 mA
Answer & Solution
Correct answer: B. 0.400 mA
1. Use Ohm's law: I = V/R.
2. Convert the resistance: 300 kilohms = 300,000 ohms.
3. Divide: I = 120 V / 300,000 ohms = 0.000400 A.
4. Convert to milliamperes: I = 0.400 mA.
5. That is below the 1-mA threshold of sensation, so the shock passes unfelt; 40.0 mA is the trap of treating 300 kilohms as 3,000 ohms.
_Source: OpenStax College Physics (CC BY 4.0), Ch 20 "Electric Current, Resistance, and Ohm's Law", section 20.6 Electric Hazards and the Human Body_
Related questions
Two wires of identical shape but different metals carry different currents at the same volA battery supplies a constant voltage, which makes the circuit it drives:Electric energy and electric power are connected by treating power as a rate of:A current of 3 amperes means charge passes a point at a rate of:Two of the three electric power expressions are restricted because they can be used only fOf the three expressions given for electric power, how many are valid for any circuit elemFuses and circuit breakers are rated in which unit?Lightbulbs are commonly rated in which unit?