This memory aid covers Memory Aid 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 13 of 17 in this topic. Use it for quick recall, then test yourself straight afterwards so the memory aid becomes usable in an answer.
Topic position
Section 13 of 17
Practice
13 questions
Recall
30 flashcards
🧠 Memory Aid
Wire colours — "Brown Lives, Blue Neutral, Green-Yellow Earth":
Brown = Live (Be careful — it's Lethal!)
Blue = Neutral (think: bland/safe at 0 V)
Green/Yellow = Earth (think: grass and sun = the earth and ground)
Fuse selection rule — "Just Above, Never Below":
Calculate the normal current using I = P/V. Choose the fuse that is just above this value from the available options (3 A, 5 A, 13 A). Never choose one that's below — it would blow immediately. Never choose one that's much higher — it won't protect.
Earth wire purpose — "Earth Escapes, Fuse Finishes":
The Earth wire provides an escape route for fault current. The large current then causes the Fuse to Finish (melt), cutting the circuit.