Transferring energy

• Entry Level Certificate
• Learning objectives


  Know the units in which electricity is sold<|>Understand what affects how much energy an appliance transfers<|>Calculate the energy transferred by an appliance
• Energy transfer by appliances

  • Depends on the power of the appliance
  • Depends on how long it is left on for
• Common household appliances


  • Refrigerator
  • Hairdryer
  • Microwave
  • Tumble dryer
  • Television
  • Iron
  • Mobile phone charger
• Electricity meters in homes measure the energy transferred in kilowatt hours
• Calculating energy transferred


  Energy transferred (kWh) = Power (kW) x Time (h)
• Kilo


  Means 1000
• To convert watts to kilowatts, divide by 1000
• 1000 W = 1 kW
• 200 W = 0.2 kW
• Energy transfer


  Depends on the power of the appliance and the time it is left on for
• Appliances and their energy transfer design

  • Lamp
  • Heater
  • Electric toothbrush
  • Radio
• A 200 W electric blanket left on for 4 hours transfers energy calculated using the equation energy (Wh) = power (kW) x time (h)