Fuses and earthing

Question 1

What is a surge?

Answer 1

• A sudden increase in current caused by a fault in the circuit or appliance

Question 2

How do fuses and circuit breakers work?

Answer 2

• They break the circuit if the current gets too high
• Fuse:
• Very thin wire which joins the live wire. If the current gets to high, the wire heats up and melts, breaking the circuit
• Very cheap but get permenantly broken
• Circuit breaker:
• When the current gets too high, it gets tripped and the circuit stops. Can easilt be reset
• More expensive than fuses but can be reused

Question 3

How does earthing work?

Answer 3

• Earth wire provides and alternate pathway for the current incase the live wire comes loose and touches the casing

Question 4

How does double insluation work (casing)?

Answer 4

• Entire appliance is insluated in a plastic casing. Plastic cannot conduct electricity so you cannot get electrocuted