Thermodynamics is the branch of physics that deals with the relationships between heat, work, and energy.
Define the First Law of Thermodynamics.
The First Law states that energy cannot be created or destroyed, only transferred or converted from one form to another.
Explain the difference between an open system, closed system, and isolated system.
An open system allows both energy and matter transfer, a closed system allows only energy transfer, and an isolated system allows neither energy nor matter transfer.
What is the Zeroth Law of Thermodynamics?
The Zeroth Law states that if two systems are each in thermal equilibrium with a third system, then they are in thermal equilibrium with each other.
Define entropy.
Entropy is a measure of the disorder or randomness in a system. It increases in the natural direction of processes.
Laws of Thermodynamics:
State the Second Law of Thermodynamics.
The Second Law states that in any energy exchange or transformation, if no energy enters or leaves the system, the potential energy of the state will always be less than that of the initial state.
What is the Carnot cycle?
The Carnot cycle is a theoretical thermodynamic cycle that describes the most efficient heat engine possible.
Explain the Third Law of Thermodynamics.
The Third Law states that as the temperature of a system approaches absolute zero, the entropy of the system approaches a minimum or constant value.
Heat and Work:
Differentiate between heat and temperature.
Heat is the transfer of thermal energy between two systems, while temperature is a measure of the average kinetic energy of particles in a system.
Define 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.
What is the definition of work in thermodynamics?
In thermodynamics, work is defined as the transfer of energy that occurs when a force is applied to move an object through a distance.
Explain the concept of adiabatic process.
An adiabatic process is one in which there is no exchange of heat with the surroundings, and the change in internal energy is solely due to work done on or by the system.
Thermodynamic Cycles:
What is a heat engine?
A heat engine is a device that converts thermal energy into mechanical work.
Describe the Rankine cycle.
The Rankine cycle is a thermodynamic cycle used in steam power plants, consisting of processes like isentropic compression, constant pressure heat addition, isentropic expansion, and constant pressure heat rejection.
Explain the refrigeration cycle.
The refrigeration cycle is a thermodynamic cycle that describes the process of absorbing heat from a low-temperature reservoir and rejecting it to a high-temperature reservoir.
Thermodynamic Processes:
Define isothermal process.
An isothermal process is a thermodynamic process in which the temperature of a system remains constant.
What is an isobaric process?
An isobaric process is a thermodynamic process in which the pressure of the system remains constant.
Explain the concept of an adiabatic process.
An adiabatic process is one in which there is no heat exchange with the surroundings. The change in internal energy is solely due to work done on or by the system.
Steam Tables and Psychrometrics:
What are steam tables used for in thermodynamics?
Steam tables provide data for the properties of water and steam, such as temperature, pressure, enthalpy, and entropy.
Define dry-bulb temperature and wet-bulb temperature in psychrometrics.
Dry-bulb temperature is the temperature of air measured with a standard thermometer, while wet-bulb temperature is the lowest temperature that can be reached by evaporating water into the air.
Heat Transfer:
What are the three modes of heat transfer?
The three modes of heat transfer are conduction, convection, and radiation.
Explain conduction.
Conduction is the transfer of heat through a material without any movement of the material itself. It occurs due to the direct microscopic interaction of particles.
Describe convection.
Convection is the transfer of heat by the movement of fluids (liquids or gases) from one part of the substance to another.
What is radiation in the context of heat transfer?
Radiation is the transfer of heat energy in the form of electromagnetic waves, without the need for a material medium.
Applications and Engineering:
How does a heat pump work?
A heat pump is a device that transfers heat energy from a source to a destination using a cycle of evaporation and condensation.
Explain the concept of thermal efficiency.
Thermal efficiency is the ratio of the useful work or energy output to the total energy input in a system.
What is the purpose of a heat exchanger?
A heat exchanger is a device used to transfer heat between two or more fluids, ensuring they remain separated and do not mix.
Entropy and Availability:
What is the role of entropy in thermodynamics?
Entropy is a measure of the disorder or randomness in a system and plays a crucial role in determining the direction of spontaneous processes.
Define exergy.
Exergy is a measure of the maximum useful work that can be extracted from a system as it comes to equilibrium with its surroundings.
How is the availability of a system related to its exergy?
Availability is a measure of the useful work that can be obtained from a system, and it is related to exergy. The higher the exergy, the higher the availability of a system.