The Three Wires — What They Do
Part of Mains Electricity & Safety · GCSE GCSE Physics revision
This deep dive covers The Three Wires — What They Do within Mains Electricity & Safety for GCSE Physics. Revise Mains Electricity & Safety in Electricity for GCSE Physics with 18 exam-style questions and 30 flashcards. This topic appears less often, but it can still be a useful differentiator on mixed-topic papers. It is section 3 of 16 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 3 of 16
Practice
18 questions
Recall
30 flashcards
🔌 The Three Wires — What They Do
LIVE (Brown):
- Carries the current TO the appliance
- Alternates between +325 V and -325 V (averaging 230 V RMS)
- ALWAYS dangerous — even when appliance is "off" but plugged in!
- Has the fuse connected to it
NEUTRAL (Blue):
- Completes the circuit back to supply
- At approximately 0 V (earth potential)
- Generally safer, but still part of the circuit
EARTH (Green & Yellow):
- Safety wire — connected to metal case of appliance
- Normally carries NO current
- Only carries current if there's a fault
- Provides low-resistance path to ground — protects user
Keep building this topic
Read this section alongside the surrounding pages in Mains Electricity & Safety. That gives you the full topic sequence instead of a single isolated revision point.
Practice Questions for Mains Electricity & Safety
What does AC stand for, and how does it differ from DC?
Explain how a fuse protects an electrical circuit from damage.
Quick Recall Flashcards
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