Question Detail
Question
A wire of resistance 2Ω is stretched uniformly to twice its original length. What is the resistance of the new wire?
Correct Answer
Option D is the correct answer.
Detailed Explanation
Since volume is conserved when stretching, doubling the length halves the cross-sectional area, and R = ρL/A means R scales with L², so the new resistance is 2² × 2Ω = 8Ω.
Hint
Remember stretching a wire conserves its volume, so area shrinks as length grows — resistance scales with the square of the length change.