INPHO Thermal Physics Questions, Important Topics and How to Prepare?

INPHO Thermal Physics Questions: The Indian National Physics Olympiad (INPHO) is a premier competition that evaluates a student's deep understanding of advanced physical concepts. Among the key areas, Thermal Physics holds a central place, challenging candidates to connect macroscopic observations, like temperature and pressure, with microscopic theories involving particles and energy distributions. Mastering INPHO Thermal Physics Questions requires a solid grasp of concepts such as energy conservation, the laws of thermodynamics, entropy, and the statistical behavior of matter. 

Students must also be adept at problem-solving that involves heat engines, entropy changes, ideal and real gases, phase transitions, and kinetic theory. Excelling in this section not only tests analytical and mathematical skills but also hones the ability to visualize physical phenomena at both molecular and system levels, preparing students for higher studies and physics research.

Also Read:

• INPhO Syllabus
• INPhO Exam Date 2026

INPHO Thermal Physics Questions

Developing analytical skills is essential for solving Olympiad-level problems. Below are sample scenarios often encountered:

Q.1 to Q.4 – pH and Solubility Calculations

1. Calculate the pH of a 0.010 M solution of zinc nitrate, Zn(NO3)2.

2. Calculate the pH of a 0.010 M solution of zinc acetate, Zn(CH3COO)2. The pKa of CH3COOH is 4.75.

3. Zinc hydroxide is sparingly soluble, with Ksp=4.5×10−17K_{sp} = 4.5 × 10^{-17}Ksp​=4.5×10−17. Calculate the pH of a solution of water saturated with solid Zn(OH)2.

4. Under what circumstances, if any, will a solution of zinc acetate spontaneously form a precipitate of Zn(OH)2? If precipitation is possible, specify the conditions for spontaneity. If it is not possible, justify why.

Q.5 to Q.9 – Net Ionic and Molecular Equations

Write net equations for each reaction. Use ionic and molecular formulas, omit spectator ions, and include structural formulas for organic substances.

5. Aqueous hydrochloric acid is added to a solution of sodium hypochlorite.

6. Aluminum foil is added to a concentrated aqueous potassium hydroxide solution.

7. Metallic sodium is added to liquid ammonia in the presence of a trace amount of iron(III) nitrate.

8. Potassium tetrachloroplatinate is heated with two equivalents of aqueous ammonia.

9. Coalt-57 undergoes radioactive decay by electron capture.
   
   

Q.10 to Q.15 – Molecular Shapes, Bonding, and Boiling Points

10. Draw or describe the shapes of the molecules BF3 and NF3.

11. In all cases, the normal boiling points of the AFn molecules are lower than those of the A(CH3)n molecules. Explain why.

12. Not counting boron compounds, the trend in boiling points decreases as the central atom A moves to the right in the periodic table. Explain this trend.

13. Explain why BF3 has a higher boiling point than CF4, while B(CH3)3 has a lower boiling point than C(CH3)4.

14. Explain why the A–C bond distances decrease as A moves to the right in the periodic table.

15. Explain why the A–F bond distances increase as A moves to the right in the periodic table.

Key Topics in Thermal Physics for INPHO

To excel in this section, candidates must be proficient in the following areas:

• Laws of Thermodynamics: Deep study of the Zeroth, First, and Second laws, emphasizing cycles and efficiency.

• Kinetic Theory of Gases (KTG): Analysis of molecular speeds (RMS, average, and most probable), mean free path, and pressure-volume-temperature relationships.

• Heat Transfer: Mastery of conduction (steady-state and transient), convection, and blackbody radiation laws.

• Phase Transitions: Understanding the thermodynamics of melting, boiling, and the Triple Point.

How to Prepare for INPHO Thermal Physics?

Preparation for the Olympiad should be rigorous and systematic:

1. Understand Core Concepts

• Focus on laws of thermodynamics, kinetic theory, entropy, heat, and energy conservation.

• Learn the connection between macroscopic observations (pressure, temperature) and microscopic behavior (particle motion, statistical distributions).

2. Study  INPhO Previous Year Question Paper

• Solve past INPHO Thermal Physics Questions to get familiar with question patterns.

• Analyze solutions to understand different problem-solving approaches.

3. Practice Numerical Problems

• Solve derivations, calculations, and conceptual numericals.

• Practice problems on heat engines, refrigerators, phase changes, and ideal gases.

4. Use Reference Books and Resources

• Refer to standard textbooks and Olympiad preparation materials.

• Make use of the PDF links of INPHO Thermal Physics Questions for extra practice.

5. Develop Conceptual Thinking

• Focus on understanding why and how a process occurs, not just memorizing formulas.

• Connect thermodynamics laws with real-world phenomena.

6. Regular Revision and Mock Tests

• Revise key formulas, derivations, and concepts regularly.

• Attempt mock tests or time-bound problem sets to improve speed and accuracy.

7. Solve Advanced and Challenging Problems

• Once the basics are clear, practice higher-level problems to strengthen analytical skills.

• Focus on problems that require integration of multiple concepts.

8. Maintain a Formula and Concept Sheet

• Keep a concise sheet of important formulas, definitions, and laws.

• Use it for quick revision before exams or tests.

INPHO Thermal Physics Questions PDF Download 

Indian National Physics Olympiad (INPHO) challenges students with advanced problems in Thermal Physics, testing their understanding of energy conservation, entropy, thermodynamics, and the statistical behavior of matter.  

Solving these INPHO Thermal Physics Questions helps students strengthen both conceptual clarity and problem-solving skills. PDF link available below for easy access to practice questions and solutions to help candidates prepare effectively for the Olympiad.