Resistivity — Predicted 2026

AI-Predicted Question Angles for UPSC 2026

Based on trend analysis, current affairs, and recurring themes in Resistivity.

Combined effect of stretching and temperature change

medium

NEET often combines concepts. A question might involve a wire being stretched (changing its resistance due to geometry) and then its temperature being raised (changing its resistance due to resistivity's temperature dependence). This tests multiple aspects of resistivity and resistance in one problem, requiring a sequential application of formulas and principles. Students need to remember that resistivity is constant during stretching but changes with temperature.

Graphical representation of resistivity vs. temperature

high

Visual questions are becoming more common. A graph showing resistivity vs. temperature for a conductor, semiconductor, and an alloy (like nichrome) could be presented, and students asked to identify the material or interpret the graph. This tests conceptual understanding of temperature dependence without requiring complex calculations, making it suitable for a quick MCQ.

Application of microscopic formula for conceptual reasoning

medium

While direct calculations using $\rho = \frac{m}{ne^2\tau}$ are rare, questions asking about the effect of changing $n$ or $\tau$ (e.g., due to doping in semiconductors, or increased collisions in metals) on resistivity are possible. This tests a deeper understanding of the physical origin of resistivity beyond just the macroscopic formula. For instance, 'What happens to resistivity if electron density is halved and relaxation time is doubled?'