Question

Three samples A, B and C of the same gas initially having the same volume and pressure are expanded to double their initial volume. One sample A is expanded isothermally, B is expanded adiabatically and C is expanded isobarically. In which case is the work done minimum?

Answer 1

The Joule expansion (also known as free expansion) is a thermodynamic process in which a volume of gas is retained in one side of a thermally isolated container (through a tiny partition) while the other side is emptied. The container's barrier between the two halves is then opened, and the gas fills the whole container.

Complete step-by-step solution:
In the case of adiabatic expansion, the least amount of labour is required.
An adiabatic process is a sort of thermodynamic process that happens without the transmission of heat or mass between the system and its surroundings in thermodynamics. An adiabatic process, unlike an isothermal process, only transmits energy to the environment as work. It is also an important thermodynamic notion since it theoretically supports the theory used to explain the first rule of thermodynamics. The thermodynamic process in which no heat is exchanged between the system and its surroundings during expansion or compression. It is possible for the adiabatic process to be reversible or irreversible. The following are the prerequisites for the adiabatic process to occur:
The system must be completely isolated from the rest of the environment.
The procedure must be completed rapidly enough to allow for adequate heat transmission. For example, gas compression within an engine cylinder is supposed to proceed so quickly that only a small portion of the system's energy is created and delivered out as heat during the compression process.
Despite the fact that the cylinders are not insulated and are conductive, the process is considered adiabatic.

Note: The term "isentropic process" refers to a reversible adiabatic process. It is an idealised adiabatic thermodynamic process in which the system's work transfers are frictionless, there is no heat or matter transfer, and the process is reversible. In engineering, such an idealised process may be used as a model and reference point for real processes. Adiabatic expansion is defined as the optimum behaviour for a closed system with constant pressure and decreasing temperature.