Physics Current Electricity UHS 2024
PMDC Verified Question 14 of 112
When length of copper wire is doubled then resistivity becomes:
A
Double
B
Half
C
Remains same
D
Four times
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option C: Remains same
Concept:

Distinguish between extensive properties (Resistance) and intensive properties (Resistivity).

Solution:

  • Resistivity (\(\rho\)) is purely a property of the material's atomic lattice and its current temperature.


  • Stretching, cutting, or doubling a wire fundamentally alters its geometric resistance (\(R\)), but it does not magically change copper into a different element.


  • Therefore, the resistivity remains the same.


Why other options are incorrect:

  • Opt A, B, D: These are incorrect assumptions that resistivity scales geometrically like resistance.

Quality & Fidelity Assurance: Every question on BeambePrep is rigorously curated against the official PMDC syllabus with zero filler, zero out-of-syllabus content, and zero typos. When an authentic past paper originally contained a historical mistake or ambiguity from the examining board (such as UHS or NUMS), BeambePrep faithfully reflects the original paper while detailing the nuance and scientific consensus in the autopsy above.

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