Exam-style question
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A student measures the electromotive force (emf) of a cell to be 12 V and the internal resistance to be 2 Ω. Calculate the terminal potential difference when the current flowing through the circuit is 3 A.
Model answer
What a good answer should say
- The terminal potential difference is 6 V.
Explanation
Why this works
The correct answer is The terminal potential difference is 6 V.. This is correct because it applies the Current electricity idea named in the question, using the required quantities and units rather than mixing current, charge, potential difference, resistance, power, or energy.
The other options are less suitable because they use the wrong electrical quantity, an incompatible unit, or a rule from a different circuit context.
Common mistake
No common mistake is linked to this question yet.