3.3 Using Electrical Energy Flashcards
What is a kilowatt hour?
The amount of energy that is transferred by a one kilowatt appliance when used for one hour
What is the equation for the amount of energy supplied to a mains appliance?
E = p X t
Where
E is the energy transferred in kWh
P is the power in kW
T is the time taken in hours
How much electrical energy, in kWh, is transferred when a 9kW shower is used for 15 minutes?
2.25 kWh
How can we calculate the energy used between readings on a house electricity meter?
Subtract the previous reading from the current reading
What equation can we use to work out the total cost of the electrical mains energy used?
Total cost = number of kWh x cost per kWh
The price of 1kWh of electrical energy is 9p. How much does it cost to use a 60W electric light for 4 hours?
2.16p
What is the amount energy used in households measured in?
Kilowatt hours
