A piston-cylinder device contains helium gas, during a reversible, isothermal process the entropy of the helium will sometimes increase.
As entropy of an ideal gas depends on pressure and temperature . Hence , entropy change during isothermal process if pressure changes . Enropy changes whenever there is a transfer of heat . The change in entropy is the heat added divided by the temperature at which the transfer took place .
A piston-cylinder is a moving device that is made tight by the piston rings. It moves inside in a cylinder in the form of liquid and later expands and then contracts.
To learn more about reversible isothermal process
https://brainly.com/question/15429172
#SPJ4