O-LevelPhysicsElectricityOct/Nov 2025Paper 1 Q341 Mark
A resistor of resistance R is connected to a variable resistor, a voltmeter and a power supply of electromotive force (e.m.f.) E. [Figure 34.1] The resistance of the variable resistor increases from 0 to 2R. What happens to the reading on the voltmeter?
AIt increases from 0 to 1/4 E.
BIt increases from 0 to 1/2 E.
CIt increases from 0 to 2/3 E.
DIt increases from 0 to E.
✓ Correct Answer
The correct answer is C: It increases from 0 to 2/3 E.
📋 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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