Chapter summary

The whole chapter in one list.

• The power of an electrical appliance is the electrical energy it uses in unit time.
• When a current I flows through an appliance under a potential difference V, its power is P = VI.
• The electrical energy it uses is E = VIt.
• The home meter measures electrical energy in kilowatt-hours (kWh).
• A kilowatt-hour is the energy used by a 1 kW appliance in an hour: 1 kWh = 3 600 000 J.