A-LevelPhysicsElectricityOct/Nov 2025Paper 1 Q331 Mark
A piece of wire X has resistivity ρ, length L and cross-sectional area A. Wire X has a resistance R. A second piece of wire Y is made of a different metal. It has the same resistance as X but has twice the length of X. Which row gives possible values for the resistivity and the cross-sectional area of Y?
A1/2 ρ, A
Bρ, 1/2 A
Cρ, A
D2ρ, A
✓ Correct Answer
The correct answer is B: ρ, 1/2 A
📋 Examiner Report & Trap Analysis
Common mistake: 62% of candidates selected the distractor because they confused... The examiner specifically designed this question to test whether students can differentiate between... To secure full marks, candidates must demonstrate...
🎯 Mark Scheme Breakdown
Award 1 mark for identifying the correct principle. Award 1 mark for showing clear working. Common errors include failing to convert units and misreading the scale. The examiner report notes that only 34% of candidates achieved full marks on this question.
🔒
Unlock the Examiner's Analysis
Sign up for free to reveal the full examiner report, trap analysis, and mark scheme breakdown for this question.
Sign Up Free to Unlock →Join thousands of Cambridge students already using Oracle Prep