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harjyot
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I know carnot's cycle is an example. but what is it exactly? a cycle in which ever part of process has a 'counter-process' please elaborate.
There are only two things that can be done to entropy. It can be moved and it can be created. "Reversal" refers only to reversal of the motion of entropy.harjyot said:I know carnot's cycle is an example. but what is it exactly? a cycle in which ever part of process has a 'counter-process' please elaborate.
Darwin123 said:In an irreversible cyclic process, entropy is created as well as moved.
Of course. I should have made it more clear.Rap said:Is this always true? Can't entropy simply be created in an irreversible process? I'm thinking of two gases like hydrogen and oxygen in a container of fixed volume and isolated. They will react irreversibly to form water vapor, creating entropy, yet no entropy has been moved.
Darwin123 said:When entropy moves from a high temperature point to a low temperature point, it releases energy in the form of work.
My mistake. I should have said:Rap said:This is only true for reversible processes, right? If I thermally connect two fixed-volume systems, entropy will flow from the high temperature system to the low temperature system, yet no work will be done. Entropy will also be created.
A reversible cyclic process is a thermodynamic process in which the system undergoes a series of changes and returns to its initial state. This means that the process is both reversible and cyclic, meaning it can be reversed and repeated multiple times without any net change in the system. The process is also considered to be reversible if it can be carried out in such a way that the system and its surroundings can be returned to their original states without any net change.
In an irreversible process, the system cannot be returned to its initial state without producing some change in the surroundings, such as an increase in entropy. This is because the process involves some dissipation of energy, resulting in a loss of work potential. In contrast, a reversible cyclic process does not involve any dissipation of energy and can be reversed without any net change in the system or its surroundings.
A reversible cyclic process is important in thermodynamics as it serves as a theoretical benchmark for the maximum amount of work that can be obtained from a system. It also helps to define the concept of thermodynamic efficiency, which is the ratio of the work output to the heat input in a reversible cyclic process.
A reversible isothermal process is a special case of a reversible cyclic process in which the temperature of the system remains constant throughout the process. In contrast, a reversible cyclic process can involve changes in temperature and other thermodynamic properties, as long as the system returns to its initial state at the end of the cycle.
In theory, any real process can be made reversible by carrying it out in an infinitely slow manner. However, this is not practical in real-world scenarios. Additionally, most real processes involve some dissipation of energy, making them irreversible. Therefore, while a reversible and cyclic process is an idealized concept, it is not commonly observed in real-world systems.