What characterizes a quasistatic process in thermodynamics?

A quasistatic process in thermodynamics is characterized by an infinitely slow rate of change, allowing the system to remain in thermal and mechanical equilibrium throughout the process. This means that at every point in the process, the system can be approximated as being in equilibrium, so any changes in state variables—like pressure, volume, and temperature—occur smoothly and gradually.

The key feature of this process is that because of the extremely slow changes, the system can adjust to external conditions without generating significant gradients in thermodynamic properties. In a practical sense, this allows for the precise application of thermodynamic laws, such as the first and second laws, over the course of the process, leading to predictable changes in state.

Other choices do not align with the definition of a quasistatic process. Rapid processes would not allow for equilibrium and would generate non-uniform temperature and pressure across the system. Similarly, high temperature variations and rapid heat transfer imply that the system is undergoing sudden changes, contradicting the fundamental characteristic of a quasistatic process achieving equilibrium throughout.