Physics Current Electricity PMDC 2020
PMDC Verified Question 83 of 112
The change in a resistance of metallic conductor below 0\(^\circ\text{C}\)?
A
Nonlinear
B
Curve
C
Linear
D
Curvilinear
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option C: Linear
Concept:

The resistance of typical metallic conductors (like copper or platinum) follows a specific empirical relationship with temperature.

Solution:

  • For typical metallic conductors, the change in resistance with respect to temperature is approximately linear over a wide range of temperatures, including somewhat below 0\(^\circ\text{C}\) (until very near absolute zero where it curves or drops to zero in superconductors).


  • The standard formula \( R_t = R_0(1 + \alpha t) \) is the equation of a straight (linear) line.


Why other options are incorrect:

  • Opt A, B, D: While strictly non-linear at cryogenic temperatures, standard syllabus models this behavior as linear for standard metallic conductors.

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.

Previous Question All Current Electricity MCQs Next Question

Want to solve full-length papers under timed exam conditions?

Practice with zero-scroll lockdown sprints, dynamic latency zone timers, live peer selection telemetry, and the automated Amber mistake recovery loop.

Enter Arena Sprint iOS App Android App