Fuses and Earthing

• What is a common problem when dealing with electricity?

  Sudden increases in current, called surges
• What can cause surges in electrical circuits?

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

  Fires and electric shocks
• What safety precautions can reduce electrical risks?

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

  They both break the circuit during surges
• What is a fuse made of?

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

  The thin wire melts, breaking the circuit
• What do fuses come in?

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

  A 5 amp fuse
• Why should a fuse rating be above the appliance's current?

  To prevent unnecessary circuit breaks
• What is a disadvantage of fuses compared to circuit breakers?

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

  Circuit breakers can be reset after tripping
• What can happen if a live wire comes loose in an appliance?

  It can touch the casing, causing shocks
• What is the purpose of earthing in electrical safety?

  To provide an alternative pathway for current
• How does double insulation prevent electric shocks?

  It covers the appliance in non-conductive material
• What type of wire does a double insulated appliance have?

  Live and neutral wires only
• What are the benefits and downsides of fuses and circuit breakers?

  Benefits of fuses:

  • Simple and cheap
  • Common in appliances

  
  

  Downsides of fuses:

  • Permanently broken after a surge

  
  

  Benefits of circuit breakers:

  • Can be reset after tripping

  
  

  Downsides of circuit breakers:

  • More expensive than fuses