Exam-style question
Try this first
A charge of 4.0 C transfers 12 J of energy. Which value is the potential difference?.
- A.3.0 V, because V = E / Q = 12 / 4.0.
- B.48 V, because energy and charge have been multiplied.
- C.0.33 V, because charge has been divided by energy.
- D.12 A, because the answer confuses potential difference with current.
Model answer
What a good answer should say
- The correct option is 3.0 V, because V = E / Q = 12 / 4.0.
Explanation
Why this works
The other options confuse potential difference with current, force, resistance, power, or a missing-unit answer.
Common mistake
No common mistake is linked to this question yet.