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 electrical surges?

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

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

  Both break the circuit during high current
• 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, what fuse could you use?

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

  To avoid breaking during normal operation
• What is a downside of fuses?

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

  They can be reset after tripping
• What is a disadvantage of circuit breakers?

  They are more expensive than fuses
• How can surges cause harm in appliances?

  If the live wire touches the casing
• What is the purpose of earthing in electrical safety?

  To divert current away from users
• What type of wire does a double insulated appliance have?

  Live and neutral wire only
• What does double insulation do for an appliance?

  Covers it in plastic to prevent shocks
• What are the key features of fuses and circuit breakers?

  Fuses:

  • Simple and cheap
  • Permanently broken after a surge

  
  

  Circuit Breakers:

  • Can be reset
  • More expensive than fuses