When performing a circuit test, what is the primary function of a voltmeter?

The primary function of a voltmeter is to measure voltage across components in an electrical circuit. This tool is essential for diagnosing problems within the circuit, as it provides insight into whether voltage levels are appropriate and consistent. When a voltmeter is connected across two points in a circuit, it can reveal the potential difference (voltage) between those points. This ability to measure voltage is vital for ensuring that components are receiving the correct amount of electrical power, which directly affects their operation and performance.

Understanding this role is crucial for electricians and technicians, as it helps them troubleshoot and confirm circuit functionality. For instance, if a component is not operating correctly, checking the voltage across it can indicate whether it is receiving the necessary electrical supply. A low or zero voltage reading might suggest a fault in the circuit or a poor connection. Hence, knowing how to effectively use a voltmeter is an important skill in electrical maintenance and repair.