This deep dive covers Choosing the Right Fuse 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 6 of 16 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
🧮 Choosing the Right Fuse
Step 1: Calculate normal operating current using I = P / V
Step 2: Choose fuse rating just ABOVE this current
Example: A 2000 W kettle at 230 V:
- I = P/V = 2000/230 = 8.7 A
- Available fuses: 3 A, 5 A, 13 A
- Choose: 13 A (next size up from 8.7 A)
Why not 5 A? Normal current (8.7 A) would blow it immediately! Fuse must be above normal current but below dangerous levels.
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.