THIRD SEMESTER PHYSICS
HEAT AND THERMODYNAMICS
UNIT-I: Kinetic Theory of gases: (12 hrs)
Kinetic Theory of gases-Introduction, Maxwell's law of distribution of molecular velocities (qualitative treatment only) and its experimental verification,Mean free path, Degrees of freedom, Principle of equipartition of energy (Qualitative ideas only), Transport phenomenon in ideal gases: viscosity, Thermal conductivity and diffusion of gases.
UNIT-II: Thermodynamics: (12hrs)
Introduction- Isothermal and Adiabatic processes, Reversible and irreversible processes, Carnot’s engine and its efficiency, Carnot’s theorem, Thermodynamic scale of temperatureand its identity with perfect gas scale, Second law of thermodynamics: Kelvin’s and Clausius statements, Principle of refrigeration, Entropy, Physical significance, Change in entropy in reversible and irreversible processes; Entropy and disorder-Entropy of Universe; Temperature-Entropy (T-S) diagram and its uses ; change of entropy when ice changes into steam.
UNIT-III: Thermodynamic Potentials and Maxwell’s equations: (12hrs) Thermodynamic potentials-Internal Energy, Enthalpy, Helmholtz Free Energy, Gibb’s Free Energy and their significance, Derivation of Maxwell’s thermodynamic relations from thermodynamic potentials, Applications to (i) Clausius-Clayperon’s equation (ii) Value of CP- CV (iii) Value of CP/CV (iv) Joule-Kelvin coefficient for ideal and Vander Waals’ gases
UNIT-IV: Low temperature Physics: (12hrs) Methods for producing very low temperatures, Joule Kelvin effect, Porous plug experiment , Joule expansion, Distinction between adiabatic and Joule Thomson expansion, Expression for Joule Thomson cooling, Liquefaction of air by Linde’s method, Production of low temperatures by adiabatic demagnetization (qualitative), applications of substances at low temperatures.
UNIT-V: Quantum theory of radiation: (12 hrs) Blackbody and its spectral energy distribution of black body radiation, Kirchoff’s law, Wein’s displacement law, Stefan-Boltzmann’s law and Rayleigh-Jean’s law (No derivations), Planck’s law of black body radiation-Derivation, Deduction of Wein’s law and Rayleigh- Jean’s law from Planck’s law, Solar constant and its determination using Angstrom pyroheliometer, Estimation of surface temperature of Sun.