A-LevelPhysicsD.C. circuitsOct/Nov 2010Paper 1 Q331 Mark
A battery of e.m.f. 12 V and internal resistance 2.0 Ω is connected in series with an ammeter of negligible resistance and an external resistor. External resistors of various different values are used. [Figure showing a battery with internal resistance, connected to an ammeter and an external resistor.] Which combination of current and resistor value is not correct?
Acurrent/A: 1.0, external resistor value/Ω: 10
Bcurrent/A: 1.2, external resistor value/Ω: 8
Ccurrent/A: 1.5, external resistor value/Ω: 6
Dcurrent/A: 1.8, external resistor value/Ω: 4
✓ Correct Answer
The correct answer is D: current/A: 1.8, external resistor value/Ω: 4
📋 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.
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