Which of the following is most commonly used to measure electrical current?

The measurement of electrical current is most commonly done using an ammeter. An ammeter is specifically designed to measure the flow of electric charge in a circuit, typically expressed in amperes. When measuring current, it is crucial to connect the ammeter in series with the circuit component whose current you wish to measure. This configuration ensures that all the current flowing through that part of the circuit also flows through the ammeter, providing an accurate reading.

Other instruments serve different purposes; for example, a voltmeter measures voltage across two points in a circuit and is designed to be connected in parallel. An ohmmeter is used to measure resistance in an electrical component, and a multimeter can perform multiple functions, including measuring voltage, current, and resistance, but it requires switching between these functions. While a multimeter can measure current, it is not the most commonly used device specifically for measuring current when a dedicated tool, like an ammeter, can provide quicker and more direct readings. Thus, the ammeter stands out as the standard instrument for current measurement in various electrical applications.