1. Electrical energy
The rate at which electrical energy is moved through a circuit is given in terms of power.
The unit for electric power is the Watt (W)

2. The common unit for electric energy is the kilowatt-hour (kW-hr)
Ex: A dishwasher draws 10. A of current from a 120-V source. The power expended by this circuit is:
The amount of electrical energy consumed by a circuit can be calculated by:
The common unit for electric energy is the kilowatt-hour (kW-hr)

3. Ex: If the dishwasher runs for 1
Ex: If the dishwasher runs for 1.5 hours each day, the cost to run it for a 30-day month, at 8 cents per kilowatt-hour, is:

4. Two other useful equation forms for calculating electric power:

5. A 2510-W air conditioner has an electrical resistance of 11. 0 Ω
A 2510-W air conditioner has an electrical resistance of 11.0 Ω. What current will it draw from the voltage source?

6. The power supplied by a voltage source is 72 W
The power supplied by a voltage source is 72 W. If the resistance of the circuit is 8.0 Ω, what is the voltage of the source?