domestic uses and safety

• Where does the majority of the UK's electricity come from?

  The national grid
• What type of current is supplied by the main supply?

  Alternating current
• What is the voltage of the main supply in the UK?

  230 volts
• What is the frequency of the main supply in the UK?

  50 hertz
• What happens when we plug an electrical appliance into a plug socket?

  It connects to the main supply
• How many wires does a typical three-core cable have inside?

  Three
• What are the three wires inside a three-core cable?

  Live, neutral, and earth
• What material are the wires in a cable made of?

  Copper
• Why are the wires coated in plastic?

  For insulation and safety
• What color is the plastic coating of the live wire?

  Brown
• What is the role of the live wire?

  Provides the alternating potential difference
• What is the approximate voltage of the live wire?

  230 volts
• What color is the plastic coating of the neutral wire?

  Blue
• What is the role of the neutral wire?

  Completes the circuit by carrying away current
• What is the potential difference of the neutral wire?

  Zero volts
• What color is the plastic coating of the earth wire?

  Striped green and yellow
• What is the normal function of the earth wire?

  Doesn't normally carry current
• What is the potential difference of the earth wire?

  Zero volts
• What is the role of the earth wire?

  Stops appliance casing becoming live
• If the live wire touches the appliance casing, what could happen?

  The casing could become live
• How does the earth wire prevent electric shock?

  Provides an alternative pathway for current
• Why does electricity pass through the neutral or earth wire?

  They have a zero volt potential difference
• Why can touching the live wire cause an electric shock?

  Humans have a potential difference of zero volts
• Why is it important to never touch plug sockets?

  The live wire always has a potential difference
• What type of current is Mains electricity in the UK?

  Alternating current (AC)
• What does alternating current mean?

  Electrons flow forward and reverse directions
• What is the frequency of alternating current in the UK?

  50 hertz
• What is the potential difference of alternating current in the UK?

  Around 230 volts
• How are electrical appliances normally connected to the main supply in the UK?

  Using Three core cable
• What material are the wires in a three-core cable made of?

  Copper
• What property of copper makes it suitable for electrical wires?

  Good conductor of electricity
• What material are the coatings of the wires made of?

  Plastic
• What property of plastic makes it suitable for coating electrical wires?

  Does not conduct electricity
• What color is the Live Wire?

  Brown
• What is the typical potential difference carried by the Live Wire?

  Around 230 volts
• What component is the Live Wire connected to in the plug?

  A fuse
• What color is the neutral wire?

  Blue
• What is the function of the neutral wire in a circuit?

  Completes the circuit with the Live Wire
• What is the potential difference of the neutral wire?

  Around 0 volts
• What color is the Earth wire?

  Green and yellow striped