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 13 exam-style questions and 30 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 4 of 17 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 4 of 17
Practice
13 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