Which device measures the electrical current flowing through a circuit?

• A. Potentiometer
• B. Voltmeter
• C. Ammeter
• D. Transformer

Answer: (C)

An ammeter is specifically designed to measure the electrical current flowing through a circuit. It is connected in series with the circuit component whose current is being measured. By doing this, the ammeter can provide a direct reading of the current in amperes (A), reflecting how much charge is flowing per second. This measurement is crucial for understanding how electrical devices operate and for diagnosing issues within a circuit.

In contrast, a potentiometer is primarily used to measure voltage or to adjust resistance. A voltmeter measures the voltage across two points in a circuit, not the current itself. A transformer, on the other hand, is used to change the voltage level in AC circuits and does not measure current. Thus, each of the other devices serves different functions, reinforcing that the ammeter is the appropriate choice for measuring electrical current.