Which device is used to measure current?

The device used to measure current is an ammeter. Ammeters are specifically designed for this purpose and are connected in series in a circuit to measure the flow of electric current. They typically have a very low internal resistance, allowing them to efficiently measure current without significantly affecting the current flow in the circuit.

In contrast, a voltmeter measures voltage and is connected in parallel across a component in a circuit. A resistor is a component used to limit or control the flow of current, and it does not measure current itself. A capacitor, on the other hand, stores electrical energy and is not used for measuring current either. Thus, the ammeter is clearly identified as the correct device for measuring current in electrical circuits.