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Third law of thermodynamics is law of entropy. It is a statement about the ability to create an absolute temperature scale, for which absolute zero is the point at which the internal energy of a solid is zero. Third law of thermodynamics states that it is impossible to reduce any system to absolute zero in…

 Entropy Defining entropy in an exact word or line is impossible. It can be viewed as a measure of molecular disorder or molecular randomness. As a system becomes more disordered, the positions of the molecules become less predictable and the entropy increases. Thus, the entropy of a substance is lowest in the solid phase and…

The efficiency of a heat engine cycle greatly depends on how the individual processes are executed. The net work can be maximized by using reversible processes. The best known reversible cycle is the Carnot cycle. Note that the reversible cycles cannot be achieved in practice because of irreversibilities associated with real processes. But, the reversible…

The efficiency of a heat engine cycle greatly depends on how the individual processes are executed. The net work can be maximized by using reversible processes. The best known reversible cycle is the Carnot cycle. Note that the reversible cycles cannot be achieved in practice because of irreversibilities associated with real processes. But, the reversible…

Second law of thermodynamics overcomes the limitations of first law of thermodynamics. First law of thermodynamics does not tell how much of heat is changed into work. Second law of thermodynamics shows that the total heat supplied to a system cannot be transferred solely into the work using single reservoir, i.e., some part of heat…

In a steady flow process, thermodynamic properties at any section remain constant with respect to time; it can vary only with respect to space. A schematic diagram of steady flow process is shown in Figure 1.7. Figure 1.7 Schematic Diagram of Steady Flow Process From continuity equation: Energy balance equation: This is known as steady flow energy…

Heat and work are energy transfer mechanisms between a system and its surroundings. Some of the similarities between heat and work are as follows: 1.4.5  Non-flow Processes The various non-flow processes and their characteristics are shown in Figure 1.3. Figure 1.3 Non-flow Processes Constant Volume Process In this process, volume remains constant, i.e., ΔV = 0. This is also…

Energy transfer across the boundary of a closed system may occur in the form of heat and work. When a closed system is left in a medium of different temperature, energy transfer takes place between the system and the surrounding until thermal equilibrium is reached. The direction of energy transfer is always from the higher…

Internal energy can be defined as the sum of all the microscopic forms of energy of a system. It is related to the molecular structure and the degree of activities at molecular level and can be viewed as the sum of the kinetic and potential energies of the molecules. Let us consider a system for…

Energy exists in various forms such as thermal, mechanical, kinetic, potential, electric, magnetic, chemical, nuclear, etc. In thermodynamics, it is considered that the various forms of energy make up total energy of a system. This total energy can be represented into two groups—macroscopic and microscopic. The macroscopic forms of energy are those a system possesses…