After this lesson, you should be able to:

• Define power as the rate at which electrical energy transfers
• Determine power output of a device as the product of the potential difference across the device and the current in the device
• Apply Ohm’s law to express the power dissipated in a  device as P=I²R
• Express the electric energy as E = Pt
• Solve circuit problems involving the concepts of electrical power and energy
• Know that the unit kilowatt-hour is a unit of energy relating to the cost of electricity
• Calculate the cost of electricity in different everyday scenarios