Ace A Level Physics 2025 – Power Up Your Physics Prowess!

The ammeter is the correct choice for measuring current in a circuit. It is specifically designed to measure the flow of electric charge through a conductor and is typically connected in series with the circuit to ensure that all of the current passes through the instrument. When current flows through the ammeter, it generates a reading that corresponds directly to the amount of current (measured in amperes) flowing in the circuit.

Other instruments, such as a voltmeter, have a different function; they measure the potential difference (voltage) between two points in a circuit and are connected in parallel. An ohmmeter is used to measure resistance in a circuit by applying a known voltage and measuring the resulting current, while a thermometer measures temperature and is unrelated to electrical measurements. Each of these instruments serves a distinct purpose in electrical measurements, highlighting the specialized role of the ammeter in current measurement.