In a reversible cycle, the entropy of the systema)increasesb)decreases...
Reversible Cycle and Entropy Change
Reversible cycle refers to a thermodynamic process that can be reversed by an infinitesimal change in a variable, such as temperature or pressure. The concept of reversible cycle is important in thermodynamics because it represents the theoretical limit of efficiency for heat engines and refrigeration cycles.
Entropy, on the other hand, is a measure of the disorder or randomness of a system. It is a state function, which means that its value depends only on the initial and final states of the system, regardless of the path taken between them. The change in entropy of a system is given by the equation:
ΔS = Q rev/T
Where ΔS is the change in entropy, Q rev is the heat transferred in a reversible process, and T is the temperature at which the process occurs.
Based on this equation, we can conclude that:
- If Q rev > 0 (heat is added to the system), ΔS > 0 (entropy increases)
- If Q rev < 0="" (heat="" is="" removed="" from="" the="" system),="" δs="" />< 0="" (entropy="" />
- If Q rev = 0 (adiabatic process), ΔS = 0 (entropy does not change)
Therefore, in a reversible cycle:
- The heat transfer occurs in a reversible process, which means that Q rev is always zero
- The temperature remains constant during the process, which means that T is always constant
- Therefore, ΔS = 0 for a reversible cycle, which means that the entropy of the system does not change.