Difficulty: Easy
Correct Answer: Second law of thermodynamics
Explanation:
ConceptThe second law sets the direction of spontaneous processes: heat flows spontaneously from higher to lower temperature.
Why others are wrongZeroth law: defines thermal equilibrium/temperature.First law: energy conservation; no directionality.Kirchhoff's law: electrical circuits, not thermodynamic direction of heat flow.
Final AnswerSecond law of thermodynamics.
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