ElectricityTopic Summary
Topic Summary: Mains Electricity and Safety
Part of Mains Electricity & Safety — GCSE Physics
This topic summary covers Topic Summary: Mains Electricity and Safety 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 17 of 17 in this topic. Use this topic summary to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 17 of 17
Practice
13 questions
Recall
30 flashcards
Topic Summary: Mains Electricity and Safety
Key Terms
- AC: Alternating current — direction reverses
- DC: Direct current — one direction only
- Fuse: Melts to break circuit if I too high
- Earth wire: Safety path for fault current
- Double insulation: Plastic case, no earth needed
Wire Colours
- Live = brown (dangerous)
- Neutral = blue (~0 V)
- Earth = green and yellow
- Fuse on the LIVE wire only
UK Mains Values
- 230 V (RMS)
- 50 Hz
- AC (not DC)
- Peak voltage ≈ 325 V (Higher)
Exam Tips
- Fuse rating: I = P/V, then choose just above
- Earth wire causes large current → blows fuse
- Circuit breaker = resettable fuse
- Double insulated = no earth needed