Power of Electric Appliances

• Domestic appliances

  • Transfer electrical energy into other forms of energy
  • Only need to identify transfers to kinetic energy and thermal energy
• Blender and fan

  Electrical energy transferred into kinetic energy of electric motors
• Iron and kettle

  Electrical energy transferred into thermal energy
• Hairdryer and washing machine

  Electrical energy transferred into both kinetic energy and thermal energy
• Appliances can be divided into two main categories: those that transfer electrical energy into kinetic energy, and those that transfer electrical energy into thermal energy</b>
• Power rating


  The rate at which energy is transferred, measured in watts (1 watt = 1 joule per second)
• Power ratings


  • Fan: 20 watts
  • Blender: 400 watts
  • Kettle: up to 2200 watts
  • Iron: up to 2400 watts
• Appliances designed to generate thermal energy usually have a much higher power rating than appliances designed to generate kinetic energy
• 2 main factors does the amount of energy transferred by an appliance depend on ?

  1. How long the appliance has been used for
• 2 main factors that allows the amount of energy transfer to n appliance ?

  - The power of the appliance
• What does a low power rating indicate?

  Less electricity an appliance uses in a given time so its cheaper to run