Thermodynamics Interview Questions 2024

Top 35 Thermodynamics Engineer Interview Questions 2024

published on
Jul 2, 2024
4 Min REad
Table of Content

Preparing for a thermodynamics engineering interview can be daunting, but with the right guidance and practice, you can excel in this stage. In this article, we will provide you with 35 Thermodynamics Interview Questions along with sample answers to help you ace your interview.

1. What is the first law of thermodynamics?

The first law of thermodynamics states that energy cannot be created or destroyed; it can only be transferred or converted from one form to another.


2. Explain the second law of thermodynamics.

The second law of thermodynamics states that the entropy of an isolated system always increases over time.


3. What is the difference between heat and temperature?

Heat refers to the transfer of energy between two substances due to a temperature difference, while temperature measures the average kinetic energy of particles in a substance.

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4. Define enthalpy.

Enthalpy is a measure of the total heat content in a system at constant pressure.


5. What is the Carnot cycle?

The Carnot cycle is an idealized thermodynamic cycle that consists of four reversible processes: isothermal expansion, adiabatic expansion, isothermal compression, and adiabatic compression.


6. How does a refrigeration cycle work?

A refrigeration cycle works by removing heat from a low-temperature space and transferring it to a high-temperature space using a refrigerant.


7. What are the different types of heat exchangers?

The different types of heat exchangers include shell and tube exchangers, plate exchangers, and finned tube exchangers.


8. Explain superheating and subcooling.

Superheating refers to heating a substance above its boiling point without changing its phase, while subcooling refers to cooling a substance below its condensing point without changing its phase.


9. What is the Rankine cycle?

The Rankine cycle is a thermodynamic cycle used in power plants to convert heat into mechanical work.


10. How do you calculate efficiency in a thermodynamic system?

Efficiency is calculated by dividing the useful output energy by the input energy and multiplying it by 100%.


11. What are the different types of thermodynamic processes?

The different types of thermodynamic processes include isothermal, adiabatic, isobaric, and isochoric processes.


12. Explain the concept of entropy.

Entropy measures the degree of disorder or randomness in a system.


13. How does a steam turbine work?

A steam turbine works by converting the thermal energy in steam into mechanical work.


14. What is a heat pump?

A heat pump is a device that transfers heat from one location to another using mechanical work.


15. Describe the Brayton cycle.

The Brayton cycle is a thermodynamic cycle used in gas turbine engines and consists of four processes: compression, constant-pressure heating, expansion, and constant-pressure cooling.


16. What factors affect thermal conductivity?

Factors that affect thermal conductivity include temperature, material properties, and sample dimensions.


17. Explain the concept of latent heat.

Latent heat refers to the amount of heat required or released during a phase change at constant temperature.


18. How does a condenser work in a refrigeration system?

A condenser in a refrigeration system works by removing heat from the refrigerant and converting it back into liquid form.


19. What are the different types of fuels used in power plants?

The different types of fuels used in power plants include coal, natural gas, oil, and nuclear fuel.


20. What is heat exchanger effectiveness?

Heat exchanger effectiveness measures the actual heat transfer compared to the maximum possible heat transfer.


21. Explain the concept of specific heat capacity.

Specific heat capacity is the amount of heat energy required to raise the temperature of a unit mass of a substance by one degree Celsius.


22. How does an air conditioning system work?

An air conditioning system works by removing heat from indoor air and transferring it outside, resulting in cool air inside.


23. What is the Clausius-Clapeyron equation used for?

The Clausius-Clapeyron equation is used to derive relationships between temperature, pressure, and changes in state for substances undergoing phase changes.


24. Describe different types of thermodynamic cycles.

Different types of thermodynamic cycles include the Carnot cycle, Rankine cycle, Otto cycle, and Diesel cycle.

25. How does a cooling tower work in a power plant?

A cooling tower in a power plant works by removing excess heat from condenser water through evaporation.


26. Explain the concept of the steady-state flow energy equation.

The steady-state flow energy equation is an energy balance equation used to analyse fluid flow systems.


27. What are some applications of thermodynamics in everyday life?

Applications of thermodynamics in everyday life include refrigerators, air conditioners, engines, and heating systems.


28. What are some challenges in thermodynamics engineering?

Some challenges include optimising energy efficiency, minimising losses during energy conversion processes, managing complex systems with multiple variables, and developing sustainable solutions to address environmental concerns.


29. How does thermodynamics relate to renewable energy sources?

Thermodynamics plays a crucial role in understanding and improving renewable energy technologies such as solar panels, wind turbines, and geothermal systems by analysing efficiency and maximising energy conversion.


30. Can you discuss any experiences or projects related to thermodynamics?

Highlight any relevant academic projects or industry experiences where you applied thermodynamics principles or worked on projects involving energy transfer or conversion.


31. How do you stay updated with advancements in thermodynamics engineering?

Mention your proactive approach to staying informed about industry trends by regularly reading research papers, attending conferences or webinars, and being part of professional engineering organisations.


32. Can you differentiate between an open system and a closed system?

An open system allows matter and energy to be exchanged with its surroundings, while a closed system only allows energy transfer but not matter exchange.


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33. Describe the working principle of a gas turbine.

A gas turbine works by compressing incoming air, mixing it with fuel, combusting it, and using the resulting high-pressure gases to drive a turbine that generates mechanical work.


34. What are some common thermodynamic cycles used in power plants?

Common thermodynamic cycles used in power plants include the Rankine cycle, Brayton cycle, and combined cycle.


35. Can you describe the working principle of an internal combustion engine?

An internal combustion engine works by igniting fuel inside a cylinder, resulting in the expansion of gases that drive pistons and produce mechanical work.


Master Thermodynamics Engineer Questions

Whether you're just starting out or looking to advance in your field, the knowledge and skills gained from studying thermodynamics can give you a competitive edge. Remember to continue learning and upskilling through degree courses in Engineering and certifications to stay ahead in this dynamic field. Speak with our experts at WiZR for personalised guidance on your career growth.



1. How much does a thermodynamics engineer earn?

Thermodynamics engineers in India can earn an average annual salary of ₹6-8 lakhs, depending on factors such as experience, qualifications, and location.

2. Can I talk about salary expectations during an interview?

It's advisable to research industry standards beforehand, but it's best to let the employer bring up the topic of salary during the interview process.

3. How can I become a thermodynamics engineer?

To become a thermodynamics engineer, you typically need a bachelor's degree in mechanical engineering or a related field. Consider pursuing further education or specialised courses to enhance your skills.

4. Where do thermodynamics engineers work?

Thermodynamics engineers work in various industries, such as energy, automotive, aerospace, manufacturing, and research organizations. They can find employment opportunities in both private companies and government sectors.

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