a) Examples of energy transfers that everyday electrical appliances are designed to bring about.
kWh calculations
c) To calculate the amount of energy transferred from the mains using:
E = P x t
E is energy transferred in joules, J
P is power in watts, W
t is time in seconds, s
This equation may also be used when:
E is energy transferred in kilowatt-hours, kWh
P is power in kilowatts, kW
t is time in hours, h
Candidates will not be required to convert between kilowatt-hours and joules.
d) To calculate the cost of mains electricity given the cost per kilowatt-hour.