energy transfers

• According to the material, what is power?

  The rate at which energy is transferred
• What is the unit of power?

  Watt
• What is one watt equivalent to in terms of energy transfer?

  One Joule per second
• In a series circuit, how is the total potential difference of the cell distributed among the resistors?

  Potential difference is shared between components
• What happens whenever charge flows in a circuit?

  Work is done, or energy is transferred
• How is potential difference shared across components in a series circuit?


  It is shared
• For a blender and a fan, what type of energy is electrical energy primarily transferred into?

  Kinetic energy
• What is the purpose of the movement in a blender?

  To mix food
• Why is electrical energy transferred into kinetic energy in blenders and fans?

  Because their main purpose is movement
• What is the purpose of the movement in a fan?

  To create air currents
• What other type of energy is generated by the motor, but is ignored for the purposes of the video?

  Thermal energy
• What type of energy is electrical energy transferred into in an iron and a kettle?

  Thermal energy
• Why is electrical energy transferred into thermal energy in irons and kettles?

  Because they are designed to get hot
• According to the video, what are the two main categories of appliances based on energy transfer?

  Kinetic and thermal energy transfers
• In a hair dryer, what component heats the air?

  Heating element
• In a hair dryer, what component moves air through it?

  A motor
• In a washing machine, what component heats the water?

  Heating element
• In a washing machine, what component turns the drum to wash the clothes?

  The motor
• What is power defined as?

  Rate at which energy is transferred
• What is the definition of one watt of power?

  One joule per second
• What type of appliances usually have a much higher power rating?

  Appliances that generate thermal energy
• According to the video, what is the power rating of the kettle?

  Up to 2,200 watts
• Why do appliances designed to generate thermal energy usually have a higher power rating?

  They need more energy to heat
• What forms of energy can electrical energy be transferred into?

  Kinetic and thermal energy
• What does the power rating of an appliance tell us?

  Joules of energy transferred every second
• How do you convert a large energy value in Joules to KiloJoules?

  Divide the energy value in Joules by 1,000.
• In the UK, what percentage of electricity comes from burning fossil fuels?

  Over 50%
• Approximately what percentage of the UK's electricity is generated from renewable sources like wind power?

  25%
• What percentage of the UK's electricity comes from nuclear power?

  Around 20%
• Where does the remainder of the UK's electricity come from?

  Imported from Europe
• What is the role of the National Grid?

  To get electricity from power stations to homes
• Approximately how many homes in the UK need to be supplied with electricity?

  Around 25 million
• According to the video, what specifically constitutes the National Grid?

  Transformers and cables
• Why is energy lost in power cables?

  Due to the resistance of the wires
• How does the distance between a power station and homes affect energy loss?

  The greater the distance, the greater the loss
• What is one way to reduce energy loss when transmitting electricity?

  Building power stations near homes
• According to the video, what is the role of step-up transformers?

  Increase the potential difference
• According to the video, what do step-up transformers increase the potential difference to?

  Several 100,000 volts
• Why is it important to say "less energy is lost" rather than "less electricity is lost"?

  Because that is the correct terminology
• According to the video, why is energy loss reduced when the potential difference is very high?

  Less energy is lost in the power cables