Second Law of Thermodynamics — Predicted 2026

AI-Predicted Question Angles for UPSC 2026

Based on trend analysis, current affairs, and recurring themes in Second Law of Thermodynamics.

Combined First and Second Law numerical problems

high

NEET often tests integrated concepts. A question might provide heat absorbed and rejected, ask for work done (First Law), and then ask for efficiency or COP (Second Law), or vice-versa. This requires students to apply both laws simultaneously, demonstrating a deeper understanding of thermodynamics. For example, given $Q_H$, $Q_C$, find $W$ and then $eta$ or $K$. Or given $eta$ and $Q_H$, find $W$ and $Q_C$.

Conceptual questions on the implications of entropy for spontaneity

medium

While direct entropy calculations are less common, conceptual questions about why certain processes are spontaneous (e.g., mixing of gases, heat flow) due to the increase in total entropy are a strong possibility. These questions test the fundamental understanding of entropy as a measure of disorder and its role in determining the direction of natural processes, moving beyond just formula application.

Comparison of efficiency/COP for real vs. ideal (Carnot) devices

medium

Questions might present a scenario with a real engine/refrigerator and ask for its efficiency/COP, then compare it to the theoretical maximum (Carnot) for the same temperature limits. This tests the understanding that real devices are always less efficient than ideal ones due to irreversibilities, reinforcing Carnot's theorem. Such questions require calculating both and then comparing.