Energy & Power
- Everyday appliances transfer energy electrically from the mains to energy stores within the appliance
- For example, in a heater, energy will be transferred to the thermal store of the heating element, and then to the thermal store of the surroundings
- The amount of energy transferred to and from an appliance depends on:
- The time 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
Examiner Tip
Remember that kilo (k) means 1000, so 1 kW = 1000 W