Question 163Electricity & Electronics - QMED

70% to pass

Circuit resistance is usually measured off-line (de-energized) with an ohmmeter. In the absence of an ohmmeter, however, resistance may be INDIRECTLY measured on-line (energized) using what meter (or meters)?

Afrequency meter
Bvoltmeter and an ammeter
Cvoltmeter only
Dammeter only
AI Explanation

The correct answer is B) voltmeter and an ammeter. When an ohmmeter is not available, resistance can be indirectly measured on-line (energized) using a voltmeter and an ammeter. By applying Ohm's law (R = V/I), the resistance can be calculated by measuring the voltage (V) across the circuit and the current (I) flowing through it. This method allows for the indirect measurement of resistance without the need to de-energize the circuit. The other options are incorrect because: A) A frequency meter does not provide any information about the resistance of a circuit. C) A voltmeter alone cannot provide enough information to calculate the resistance. D) An ammeter alone cannot provide enough information to calculate the resistance.

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Official Resources
46 CFR Electrical Engineering 46 CFR Machinery & Electrical USCG National Maritime Center
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