What does an ammeter indicate?

• A. The voltage across the battery
• B. The amount of current flowing into the battery and the amount of current being taken from the battery
• C. The temperature of the battery
• D. The resistance of the circuit

Answer: (B)

An ammeter shows how much electrical current is moving through a circuit, measured in amperes. It is placed in series so all the current flows through it, giving an accurate reading of the rate at which charge is moving. In the context of a battery, the ammeter can show current flowing into the battery (charging) or current leaving the battery (discharging). It does not measure voltage, temperature, or resistance—those are read by a voltmeter, a thermometer, and an ohmmeter (or resistance setting), respectively. So the ammeter’s job is to quantify current, not voltage, temperature, or resistance.