Which tool is essential for measuring electrical current?

An ammeter is the essential tool for measuring electrical current because it is specifically designed to measure the flow of electric charge in a circuit. When you connect an ammeter in series with the circuit, it allows for the detection of current flowing through the circuit in amperes (A). This capability is crucial in electrical troubleshooting and analysis, as it provides direct readings of current that can help diagnose issues like overloads, shorts, or insufficient current supply.

In contrast, while an ohmmeter is used to measure resistance, a voltmeter measures the potential difference between two points in a circuit. Both these tools do not provide any information about the actual current flowing in the circuit. A continuity tester checks whether electricity can flow through a circuit by testing for a complete path but does not measure the current itself. Therefore, the ammeter is the appropriate choice for measuring electrical current specifically.