Question
Question (4 marks): Explain how the earth wire and fuse together protect a user from electrocution if the live wire touches the metal casing of an appliance.
Mark scheme (any 4):
- Earth wire provides a low-resistance path from casing to ground (1)
- A large current flows through live → casing → earth (1)
- This large current melts/blows the fuse (1)
- Fuse breaks the live wire, isolating the appliance (1)
- User does not receive a shock because casing is no longer at mains potential (1)
4 marks · take your time before peeking.
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Generated by TopMyGrade AI · cross-check official sources before relying on the mark-scheme phrasing.