Energy Transfers in Appliances
- Everyday appliances transfer electrical energy from the mains to other forms of energy in the appliance
- For example, in a heater, this will transfer an electrical energy store into a thermal energy store
- The amount of energy an appliance transfers depends on:
- How long the appliance is switched on for
- The power of the appliance
- A 1 kW iron uses the same amount of energy in 1 hour as a 2 kW iron would use in 30 minutes
- A 100 W heater uses the same amount of energy in 30 hours as a 3000 W heater does in 1 hour
- As electricity passes around a circuit, energy is transferred from the power source to the various components (which may then transfer energy to the surroundings)
- As charge passes through the power supply it is given energy
- As it passes through each component it loses some energy (transferring that energy to the component)
The current transfers electrical energy from the power source and to the components
- Different domestic appliances transfer energy from batteries, such as a remote control
- Most household appliances transfer energy from the AC mains
- This can be to the kinetic energy of an electric motor. Motors are used in:
- Vacuum cleaners - to create the suction to suck in dust and dirt off carpets
- Washing machines - to rotate the drum to wash (or dry) clothes
- Refrigerators - to compress the refrigerant chemical into a liquid to reduce the temperature
- Or, in heating devices. Heating is used in:
- Toasters - to toast bread
- Kettles - to boil hot water
- Radiators - hot water is pumped from the boiler so the radiator can heat up a room
Energy transfers for a washing machine and toaster