Syllabus (PHYSICS)

Course Type: MAJ-4

Semester: 4

Course Code: BPHSMAJ04C

Course Title: Thermal Physics

(L-P-Tu): 4-2-0

Credit: 6

Practical/Theory: Combined

Course Objective: This course aims to provide students with a comprehensive understanding of the principles and concepts of thermal physics. Students will learn about thermodynamic laws, temperature, heat, and work. They will analyze the behavior of gases, phase transitions, and thermal properties of materials. The course will cover topics such as heat conduction in material, heat engines, entropy, and the kinetic theory of gases. Students will apply these principles to solve practical problems in engineering and everyday life. By the end of the course, students will be equipped to analyze and interpret thermal phenomena and appreciate their relevance in various scientific and technological applications.

Learning Outcome: By the end of this course, students will: a. Demonstrate a comprehensive understanding of the fundamental principles of thermal physics, including thermodynamic laws and heat transfer mechanisms. b. Analyze and predict the behavior of gases, liquids, and solids under varying temperature and pressure conditions. c. Comprehend the concepts of heat engines, refrigerators, and their practical applications in engineering and technology. d. Apply statistical mechanics and the kinetic theory of gases to interpret the macroscopic properties of matter at the molecular level. e. Evaluate and solve complex problems related to heat conduction, convection, and radiation in various physical scenarios. f. Develop practical skills in conducting thermal experiments and data analysis, reinforcing theoretical concepts and enhancing problem-solving abilities. g. Recognize the significance of thermal physics in various disciplines and its relevance to real-world applications in energy, environment, and technology.

Theory:

Kinetic Theory of Gases

Distribution of Velocities: Maxwell-Boltzmann Law of Distribution of Velocities in an Ideal Gas and its Experimental Verification. Doppler Broadening of Spectral Lines and Stern’s Experiment. Mean, RMS and Most Probable Speeds. Degrees of Freedom. Law of Equipartition of Energy (No proof required). Specific heats of Gases. (5 Lectures)

Molecular Collisions

Mean Free Path. Collision Probability. Estimates of Mean Free Path. Transport Phenomenon in Ideal Gases: (1) Viscosity, (2) Thermal Conductivity and (3) Diffusion. Brownian Motion and its Significance. (4 Lectures)

Real Gases

Behavior of Real Gases: Deviations from the Ideal Gas Equation. The Virial Equation. Andrew’s Experiments on CO₂ Gas. Critical Constants. Continuity of Liquid and Gaseous State. Vapour and Gas. Boyle Temperature. Van der Waal’s Equation of State for Real Gases. Values of Critical Constants. Law of Corresponding States. Comparison with Experimental Curves. P-V Diagrams. Joule’s Experiment. Free Adiabatic Expansion of a Perfect Gas. Joule-Thomson Porous Plug Experiment. Joule- Thomson Effect for Real and Van der Waal Gases. Temperature of Inversion. Joule-Thomson Cooling. (8 Lectures)

Heat conduction in solid

Variable and steady state of heat flow, thermal conductivity, thermal receptivity, thermometric conductivity, thermal conductivity of a composite. Fourier equation of heat conduction in one dimension. Steady state solution and application to Ingen Hausz’s experiments, extension to three dimensions for spherical and cylindrical heat flow. Lee’s method. Cylindrical shell method. Statement of Wiedmann-Franz’s Law. (4 Lectures)

Zeroth and First Law of Thermodynamics

Extensive and intensive Thermodynamic Variables, Thermodynamic Equilibrium, Zeroth Law of Thermodynamics & Concept of Temperature, Concept of Work & Heat, State Functions, First Law of Thermodynamics and its differential form, Internal Energy, First Law & various processes, Applications of First Law. General Relation between C_P and C_V, Work Done during Isothermal and Adiabatic Processes, Compressibility and Expansion Co-efficient. (8 Lectures)

Second Law of Thermodynamics

Reversible and Irreversible process with examples. Conversion of Work into Heat and Heat into Work. Heat Engines. Carnot’s Cycle, Carnot engine & efficiency. Refrigerator & coefficient of performance, second Law of Thermodynamics: Kelvin-Planck and Clausius Statements and their Equivalence. Carnot’s Theorem. Applications of Second Law of Thermodynamics: Thermodynamic Scale of Temperature and its Equivalence to Perfect Gas Scale. (10 Lectures)

Entropy

Concept of Entropy, Clausius Theorem. Clausius Inequality, Second Law of Thermodynamics in terms of Entropy. Entropy of a perfect gas. Principle of Increase of Entropy. Entropy Changes in Reversible and Irreversible processes with examples. Entropy of the Universe. Entropy Changes in Reversible and Irreversible Processes. Principle of Increase of Entropy. Temperature–Entropy diagrams for Cycle. Third Law of Thermodynamics. Unattainability of Absolute Zero. (7 Lectures)

Thermodynamic Potentials

Thermodynamic Potentials: Internal Energy, Enthalpy, Helmholtz Free Energy, Gibb’s Free Energy. Their Definitions, Properties and Applications. Gibbs free energy and spontaneity of a process. Surface Films and Variation of Surface Tension with Temperature, Magnetic Work. Cooling due to adiabatic demagnetization, First and second order Phase Transitions with examples, Clausius-Clapeyron Equation and Ehrenfest equations. (7 Lectures)

Maxwell’s Thermodynamic Relations

Derivations and applications of Maxwell’s Relations, Maxwell’s Relations:(1) Clausius Clapeyron equation, (2) Values of Cp-Cv, (3) TdS Equations, (4) Joule-Kelvin coefficient for Ideal and Van der Waal Gases, (5) Energy equations, (6) Change of Temperature during Adiabatic Process. (7 Lectures)

List of Practical (Any six)

1. To determine Mechanical Equivalent of Heat, J, by Callender and Barne’s constant flow method.

2. To determine the Coefficient of Thermal Conductivity of Cu by Searle’s Apparatus.

3. To determine the Coefficient of Thermal Conductivity of Cu by Angstrom’s Method.

4. To determine the Coefficient of Thermal Conductivity of a bad conductor by Lee andCharlton’s disc method.

5. To determine the Temperature Coefficient of Resistance by Platinum Resistance Thermometer (PRT).

6. To study the variation of Thermo-Emf of a Thermocouple with Difference of Temperature of its Two Junctions.

7. To calibrate a thermocouple to measure temperature in a specified Range using (1) Null Method, (2) Direct measurement using Op-Amp difference amplifier and to determine Neutral Temperature.

Reading References

Theory

1. Heat and Thermodynamics, M W Zemansky, R Dittman, McGraw Hill.

2. Concepts in Thermal Physics, S J Blundell and K M Blundell, 2^nd Edition, Oxford University Press.

3. An Introduction to Thermal Physics, D. V. Schroeder, Oxford University Press.

4. Thermal Physics, S. Garg, R. Bansal and S K Ghosh, 2^nd Edition, Tata McGraw Hill.

5. The Kinetic Theory of Gases, L B Loeb, Radha Publication House.

6. Thermal Physics, A B Gupta and H P Roy, Books and Allied Pvt Ltd.

7. Thermodynamics, Kinetic Theory, Statistical Thermodynamics, F W Sears and G L Salinger, Narosa.

8. Thermal Physics, C Kittel and H Kroemer, W H Freeman Publisher.

9. Thermodynamics and an Introduction to Thermostatistics, H. B. Callen, Wiley.

Practical

1. Advanced Practical Physics for Students, B L Flint and H T Worsnop, Asia Publishing House

2. A Text Book of Practical Physics, I. Prakash and R Krishna, Kitab Mahal.

3. Advanced Practical Physics, B Ghosh and K G Mazumdar, Shreedhar Prakashani.

4. An Advanced Course in Practical Physics: D Chattopadhyay and P C Rakshit, NCBA.

5. Laboratory Manual of Physics, Vol 1, M Jana, Books and Allied Pvt Ltd.