This key facts covers Key Facts Summary 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 9 of 16 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
📋 Key Facts Summary
- UK mains: 230 V AC, 50 Hz
- Live wire: brown — carries alternating voltage
- Neutral wire: blue — returns to supply at ~0 V
- Earth wire: green and yellow — safety wire, normally no current
- Fuse on the live wire (to cut the dangerous wire)
- Choose fuse just above normal operating current
- Double insulation: plastic case, no earth wire needed
- Circuit breaker: can be reset; fuse must be replaced
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
What is AC?
Alternating Current — current direction reverses constantly (50 times/second in UK)
What is DC?
Direct Current — current flows in one direction only (batteries provide DC)