A quasi-static process is defined as the process in which deviation from thermodynamic equilibrium is infinitesimal and all the states through which passes during a quasi-static process may be treated as equilibrium states.
Thus, it may be defined as
“a succession of equilibrium states.”
For example, Consider a system, a gas contained in a cylinder fitted with a movable piston. If the piston is pushed in very rapidly, the gas immediately behind the piston acquires kinetic energy & is set into turbulent motion which is a non -equilibrium state.
In such a case the work done on the system is not quasi-static and is not governed by the equation dW= PdV. If however, the piston is pushed in infinitely slow rate, the system is in equilibrium state all the time & then the process can be considered quasi-static.
Some points on Quasi-Static Process:-
1. A process of change in state variable of the system, which is infinitesimally slow is called Quasi-Static process. Quasi-Static means nearly static.
2. In this process the thermodynamical variables of the system changes so slowly that the system continues to be in thermal & mechanical equilibrium.
3. Quasi-Static process is only an idealised process in which we imagine that every state of system is in thermal equilibrium.
4. It is hypothetical construct. The process can be done in infinite number of steps & it should not involve large temperature difference & accelerated motion of the piston.
Thus, In this post we discussed about Quasi-Static process, any question, query, feedback,suggestions tell us in comment section.