Exam-style question
Try this first
What happens to the resistance of a wire if its cross-sectional area is doubled while keeping the length constant?.
- A.Resistance doubles
- B.Resistance halves
- C.Resistance remains the same
- D.Resistance quadruples
Model answer
What a good answer should say
- Resistance halves
Explanation
Why this works
The correct answer is Resistance halves. 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.