1. What is the First Law of Thermodynamics?
The First Law of Thermodynamics, also known as the Law of Energy Conservation, states that energy cannot be created or destroyed, but it can be transferred or transformed from one form to another.

2. Define the Second Law of Thermodynamics.
The Second Law of Thermodynamics states that the total entropy of an isolated system can never decrease over time, and in a spontaneous process, the entropy always increases.

3. Differentiate between an open and closed system.
In an open system, energy and matter can be exchanged with the surroundings. On the other hand, a closed system allows only the exchange of energy with the surroundings but not matter.

4. Explain the concept of entropy.
Entropy is a measure of the randomness or disorder in a system. It is related to the number of possible microscopic states that a system can reach under a given set of macroscopic conditions.

5. What is enthalpy?
Enthalpy (H) is the amount of heat or energy absorbed or released by a system at constant pressure. It comprises the internal energy of the system plus the pressure multiplied by the volume.

6. Define heat capacity.
Heat capacity is the amount of heat required to raise the temperature of a substance by one degree Celsius. It is expressed in units of energy per unit temperature.

7. What is the difference between heat and temperature?
Heat is the transfer of energy from one object to another due to a temperature difference, while temperature is a measure of the average kinetic energy of the particles in a substance.

8. Explain the concept of a Carnot cycle.
A Carnot cycle is a theoretical thermodynamic cycle that represents the most efficient operation of any heat engine working between two constant temperature reservoirs. It consists of four reversible processes: isothermal expansion, adiabatic expansion, isothermal compression, and adiabatic compression.

9. What is a heat pump?
A heat pump is a device that transfers thermal energy from a colder reservoir to a hotter reservoir by utilizing external work. It operates in a manner opposite to a refrigerator, which removes heat from inside and transfers it outside.

10. Define the coefficient of performance (COP) of a heat pump.
The coefficient of performance of a heat pump is the ratio of the heat transferred to the hot reservoir to the work input required to transfer the heat. It indicates the efficiency of the heat pump.

11. Explain the concept of specific heat.
Specific heat is the amount of heat required to raise the temperature of a unit mass of a substance by one degree Celsius. It is expressed in units of energy per unit mass per unit temperature.

12. What is a phase diagram?
A phase diagram is a graphical representation that shows the conditions of temperature and pressure under which different phases of a substance exist, such as solid, liquid, and gas.

13. Explain the concept of latent heat.
Latent heat refers to the heat energy absorbed or released during a phase change of a substance, such as melting or vaporization, without any change in temperature. It is associated with the potential energy of the molecules.

14. Define the concept of work in thermodynamics.
In thermodynamics, work is defined as the transfer of energy from one system to another due to the application of a force over a distance. It can be calculated as the product of force and displacement.

15. What is the significance of the Kelvin scale in thermodynamics?
The Kelvin scale is an absolute temperature scale used in thermodynamics. It starts from absolute zero, where all molecular motion ceases. It is advantageous as it represents temperature differences without negative values.

16. Explain the concept of reversible and irreversible processes.
In a reversible process, the system and surroundings can be returned to their initial states by reversing the changes, and there is no increase in entropy. In contrast, an irreversible process cannot be reversed precisely, and it leads to an increase in entropy.

17. Define the concept of exergy.
Exergy is a measure of the maximum useful work that can be obtained from a system as it comes to equilibrium with the surroundings. It takes into account both the energy and entropy of the system.

18. What is a heat exchanger?
A heat exchanger is a device used for the efficient transfer of heat from one fluid to another. It allows the exchange of heat without mixing the two fluids.

19. Explain the concept of a reversible heat engine.
A reversible heat engine is an idealized engine that operates in a manner opposite to a heat pump. It is an engine that extracts heat from a high-temperature source and completely converts it into work, without any energy loss.

20. What is the role of thermodynamics in engineering?
Thermodynamics plays a crucial role in engineering as it helps in understanding energy conversion, heat transfer, and power generation in various systems. It enables engineers to optimize processes, design efficient systems, and make informed decisions regarding energy utilization.

1. What is the difference between reversible and irreversible processes in thermodynamics?
Reversible processes are idealized processes that occur very slowly and involve no energy losses, whereas irreversible processes occur quickly and involve energy losses due to friction, heat transfer, etc.

2. Define the term ‘Enthalpy’.
Enthalpy is the total heat content of a system, including both internal energy and the energy required to overcome pressure-volume work.

3. Explain the concept of entropy.
Entropy is a thermodynamic property that measures the degree of randomness or disorder in a system. It increases in a closed system over time.

4. What is the Clausius inequality? What does it signify?
The Clausius inequality states that the integral of dq/T for a closed system is always greater than or equal to zero. It signifies the direction of a process, whether it is reversible or irreversible.

5. Can you give an example of a reversible process?
An example of a reversible process is an ideal gas expanding or compressing at a very slow rate.

6. Define the term ‘Carnot cycle’.
The Carnot cycle is a theoretical thermodynamic cycle consisting of four reversible processes, namely adiabatic expansion, isothermal expansion, adiabatic compression, and isothermal compression.

7. What is the efficiency of a Carnot cycle?
The efficiency of a Carnot cycle is given by the formula: efficiency = 1 – (Tc/Th), where Tc is the absolute temperature of the cold reservoir and Th is the absolute temperature of the hot reservoir.

8. State the second law of thermodynamics.
The second law of thermodynamics states that the entropy of an isolated system always increases in a spontaneous process.

9. How is the coefficient of performance (COP) defined for a refrigeration cycle?
The coefficient of performance (COP) for a refrigeration cycle is defined as the ratio of desired cooling effect q1 to the work input W: COP = q1/W.

10. What is the meaning of a thermodynamic property?
A thermodynamic property is a characteristic or attribute of a system that can be used to define its state. Examples include temperature, pressure, volume, and internal energy.

11. Explain the concept of latent heat.
Latent heat is the amount of heat energy required to change the state of a substance without changing its temperature. It is directly related to phase transitions, such as from solid to liquid or liquid to gas.

12. What is the difference between specific heat and heat capacity?
Specific heat is the amount of heat energy required to raise the temperature of a unit mass of a substance by one degree, while heat capacity is the amount of heat energy required to raise the temperature of a given substance by one degree.

13. Define adiabatic process and give an example.
An adiabatic process is one in which no heat is exchanged with the surroundings. An example is the compression or expansion of a gas in a perfectly insulated container.

14. What is the difference between open and closed systems in thermodynamics?
In thermodynamics, an open system can exchange both matter and energy with its surroundings, while a closed system can only exchange energy but not matter.

15. Explain the concept of exergy.
Exergy is the maximum useful work that can be obtained from a system at a given state, relative to the environment. It provides a measure of the quality or potential of energy.

16. What is the significance of the Joule-Thomson effect?
The Joule-Thomson effect describes the change in temperature of a gas when it expands or throttles through a valve or porous plug. It is used in refrigeration and liquefaction processes.

17. What is the Maxwell’s relations in thermodynamics?
Maxwell’s relations are a set of equations derived from the basic thermodynamic potentials, which relate partial derivatives of thermodynamic variables to each other.

18. What is the Gibbs-Duhem equation?
The Gibbs-Duhem equation is a mathematical relationship derived from the first and second laws of thermodynamics, which relates changes in extensive properties like the chemical potential, pressure, and temperature.

19. Explain the concept of a heat engine.
A heat engine is a device that converts thermal energy into mechanical work by exploiting the temperature difference between a high-temperature reservoir and a low-temperature reservoir.

20. Define the term ‘adiabatic flame temperature’.
Adiabatic flame temperature is the highest temperature that can be achieved by a combustion process when no heat is lost to the surroundings. It occurs under the assumption of complete combustion.