Zusammenfassung der Ressource
The Usefulness of Electrical Appliances
- We often use electrical
appliances because they transfer
energy at the flick of a switch
- We can calculate how much energy
is transferred by an appliance and
how much the appliance costs to run
- Transferring electrical energy
- The amount of energy an appliance transfers
depends on how long the appliance is switched
on for and its power
- To calculate the amount of energy transferred from the
mains we use; E= P*t
- If E is energy transferred in kilowatt hours (kWh), P is the
power in kilowatts (kW) and t is time in hours (h)
- If E is energy transferred in joules (J), then P is power in
watts (W) and t is time in seconds (s)
- Cost of Electricity
- Electricity meters measure the number of
units of electricity used in a home or any
other building
- The cost of electricity is calculated as:
total cost= number of units*cost per unit