National Oilheat Research Alliance (NORA) Bronze Certification Practice Exam

The voltmeter is specifically designed to measure voltage in a circuit. It is connected in parallel with the component or section of the circuit where the voltage is to be measured. By doing this, it accurately reflects the electrical potential difference across that segment. The operation of a voltmeter relies on its ability to minimize the impact it has on the circuit itself, often incorporating a very high internal resistance to avoid drawing significant current that could alter the voltage being measured.

An ammeter measures current, which is the flow of electric charge, and is connected in series with the circuit. An ohmmeter is utilized to measure resistance and is typically disconnected from the circuit to function correctly. A multimeter can measure voltage, current, and resistance depending on its settings, but it is a combination device rather than a dedicated measurement tool specific to voltage. Therefore, while multimeters can measure voltage, the voltmeter remains the primary instrument for this specific purpose.