Which unit is used to express electric power?

Electric power is expressed in Watts, which is the correct choice. The watt is defined as one joule per second and is the standard unit for measuring the rate at which electrical energy is transferred by an electric circuit.

Understanding this concept involves recognizing the relationship between power, voltage, and current. The formula that relates these quantities is Power (P) = Voltage (V) x Current (I). Therefore, when you have voltage in volts and current in amperes, multiplying them together yields a value in watts, which quantifies how much work is done or energy consumed over time.

The other units play different roles in electrical measurements. Volts are used to measure electrical potential or voltage, Amperes measure the flow of electric current, and Ohms measure electrical resistance. Each of these units is essential in the field of electricity but does not directly measure power, which is why Watts is the correct answer in this context.