Which of the following test instruments must be used only when the circuit in not energized?
A) Ammeter
B) Ohmmeter
C) Voltmeter
D) Wattmeter

Question

Quizplus · Accepted Answer

The Ohmmeter is used to measure resistance in a circuit, which means that it sends a small amount of current through the circuit to make a measurement. If the circuit is energized, this current could cause damage to the instrument, the circuit, or both. Therefore, the Ohmmeter should only be used when the circuit is not energized. The other instruments (A) Ammeter, (C) Voltmeter, and (D) Wattmeter, measure current, voltage, and power, respectively, and do require the circuit to be energized in order to make measurements.

Which of the Following Test Instruments Must Be Used Only