What device is used to measure current flowing through a wire or circuit?

Answer: B — Ammeter

The device used to measure current flowing through a wire or circuit is an ammeter. When connected in series with the circuit, the ammeter can accurately measure the flow of electric charge, providing readings in amperes (A). This is crucial in various electrical applications as it helps technicians and engineers understand how much current is being consumed by different components in a circuit, which allows for proper analysis and troubleshooting. In contrast, a voltmeter measures the voltage across two points in a circuit, while an ohmmeter measures resistance within a circuit or component. A capacitor meter is specialized for measuring the capacitance of capacitors, not current flow. Understanding the function of each device is essential for effectively diagnosing electrical systems.