Electrical power Physics: AQA GCSE (9-1)

• Electrical power

  The amount of energy transferred by an electrical appliance each second

  
• Two things the amount of energy an appliance transfers depends on

  How long the appliance is switched on for and the power of the appliance
• P = E/t

  The equation linking power, energy transferred and time

  
• One watt is equal to


  The power when one joule of energy is transferred in one second (1 W = 1 J/s)

  
• E = IVt

  The equation linking energy transferred, current, potential difference and time

  
• 230 V


  The potential difference of mains electricity and electrical appliances

  
• Power rating


  The power of an electrical appliance; usually given watts (W) or kilowatts (kW)

  
• Watts (W)


  The SI unit for power

  
• One kilowatt (kW) is equal to _____ watts (W)

  1000 watts (W)

  
• Seconds (s)


  The SI unit for time

  
• One hour (h) is equal to _____ seconds (s)


  3,600 seconds (s)
• Kilowatt-hour (kWh)


  The unit used for energy transferred when power is in kilowatts and time is in hours (electricity is charged per kWh)

  
• One kilowatt-hour (kWh) is equal to _____ joules (J)

  3,600,000 joules (J)