Exam-style question
Try this first
In a circuit with a potential difference of 9 V and a current of 2 A, calculate the resistance.
Model answer
What a good answer should say
- The resistance in the circuit is 4.5 Ω.
Explanation
Why this works
The correct answer is The resistance in the circuit is 4.5 Ω.. 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.