Fuses and Earthing

• What is a common problem when dealing with electricity?

  Sudden increases in current, called surges
• What can cause surges in a circuit?

  Changes in the circuit or faults in appliances
• What are the potential dangers of surges?

  Fires or electric shocks
• What safety precautions help reduce risks from surges?

  • Fuses
  • Circuit breakers
  • Earth wires
  • Double insulation
• How do fuses and circuit breakers function?

  They break the circuit when current is too high
• What is a fuse made of?

  A very thin piece of wire
• What happens to a fuse during a surge?

  It melts and breaks the circuit
• What do fuses come in?

  A range of different ratings
• If an appliance has a 3 amp current, which fuse could you use?

  A 5 amp fuse
• What is the benefit of using fuses?

  They are simple and cheap
• What is a downside of fuses?

  They are permanently broken after a surge
• How do circuit breakers differ from fuses?

  They can be reset instead of replaced
• What happens when a circuit breaker trips?

  The circuit turns off
• What is a risk associated with loose live wires?

  They can cause electric shocks
• What is the purpose of earthing?

  To provide an alternative pathway for current
• How does an earth wire help prevent electric shocks?

  It diverts electricity away from us
• What is double insulation in appliances?

  Covering the appliance in plastic casing
• What is the benefit of double insulation?

  No exposed metal parts to touch
• What wires does a double insulated appliance have?

  Live and neutral wires
• What are the main safety features to prevent electric shocks?

  • Fuses
  • Circuit breakers
  • Earth wires
  • Double insulation