Which of the following is an irreversible process?

$A$ container with insulating walls is divided into two equal parts by a partition fitted with a valve. One part is filled with an ideal gas at a pressure $P$ and temperature $T$,whereas the other part is completely evacuated. If the valve is suddenly opened,the pressure and temperature of the gas will be

Explain the quasi-static process.

When a gas in a vacuum chamber expands suddenly,which of the following is true?

$A$ process can be reversible if

Which of the following processes is reversible?