A-LevelPhysicsD.C. circuitsOct/Nov 2025Paper 1 Q361 Mark
A potentiometer circuit is used to determine the electromotive force (e.m.f.) E_X of a cell. The circuit includes a second cell of known e.m.f. E₀ and negligible internal resistance, and a uniform resistance wire PQ of known length. E_X is less than E₀. The movable connection J can be positioned anywhere along the length of the resistance wire. Which circuit is suitable for determining E_X?
A[Diagram option A]
B[Diagram option B]
C[Diagram option C]
D[Diagram option D]
✓ Correct Answer
The correct answer is D. This question tests the candidate's understanding of d.c. circuits within the Physicssyllabus. The examiner's mark scheme requires...
📋 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...
🔒
Unlock the Examiner's Answer
Sign up for free to reveal the correct answer, the official mark scheme breakdown, and the examiner trap analysis for this question.
Sign Up Free to Unlock →Join thousands of Cambridge students already using Oracle Prep