Electric current is measured in what units?

• A. Volts
• B. Amps
• C. Ohms
• D. Watts

Answer: (B)

Electric current is the rate at which electric charge flows through a conductor, and its size is measured in amperes. An ampere, often shortened to amp, is defined as one coulomb of charge passing a point every second. This is why an ammeter reads current in amps when placed in series in a circuit. The other units refer to different quantities: volts measure electric potential difference (the pressure that pushes charges), ohms measure resistance (how much a material resists current), and watts measure power (how much work per unit time the circuit does). As a practical note, power equals voltage times current, so knowing the current in amps and the voltage lets you calculate the power in watts. For the question about units of electric current, amperes are the correct choice.