Who first proposed a law in 1931 to clarify the idea of thermal equilibrium and its significance in determining temperature?

Correct option is D

The correct answer is (d) Ralph H. Fowler
Explanation: • Ralph H. Fowler proposed a thermodynamic law in 1931. • He clarified the concept of thermal equilibrium. • His work strengthened the theoretical basis for defining temperature. • Fowler contributed significantly to statistical mechanics. • His insights helped unify thermodynamics and quantum theory.
Information Booster: • Thermal equilibrium means no net heat exchange between bodies in contact. • Temperature becomes the property determining heat flow direction.
Additional Knowledge: (a) Hugh L. Callendar → Known for work on steam tables. (b) James P. Espy → Pioneer in meteorology. (c) Rudolf Clausius → Introduced entropy, but not this 1931 law.