Course info

Thermal Physics is the study of heat, temperature, and energy transfer between systems, focusing on how matter behaves when subjected to changes in heat and work. The course introduces the fundamental principles of thermodynamics, beginning with the Zeroth Law, which defines temperature and thermal equilibrium, and progresses through the First and Second Laws of Thermodynamics, dealing with energy conservation, heat-work relationships, and entropy.

Students learn the concepts of systems and surroundings, macroscopic and microscopic descriptions of matter, and how these lead to the sciences of thermodynamics and statistical mechanics. The course explains work, heat, and internal energy, establishing the First Law of Thermodynamics (ΔU = Q – W) as a statement of energy conservation. It further introduces thermodynamic cycles, such as the Carnot cycle, and examines heat engines, refrigerators, and their efficiencies, providing the foundation for understanding real-world energy conversion systems.

The Second Law of Thermodynamics and the concept of irreversibility are discussed in depth, highlighting natural processes, reversible and irreversible systems, and the emergence of entropy (S) as a measure of disorder and energy distribution. The course then introduces thermodynamic potentials—including internal energy, Helmholtz free energy, enthalpy, Gibbs free energy, and Landan (grand) potential—and their applications in analyzing equilibrium conditions and chemical reactions.

Further, Maxwell’s Relations are derived from thermodynamic potentials, connecting key variables such as pressure, temperature, entropy, and volume, and serving as a bridge between macroscopic thermodynamics and microscopic physical laws.

In the later part, the course explores the behavior of ideal and real gases, introducing the ideal gas law (PV = nRT) and Van der Waals’ equation for real gases. It examines the deviations caused by molecular interactions and finite molecular size. Finally, the Kinetic Theory of Gases provides a microscopic interpretation of temperature and pressure, relating them to the average kinetic energy of gas molecules and introducing Boltzmann’s constant and the Maxwell–Boltzmann distribution of molecular velocities.