Reversible thermodynamic process
= Reversible thermodynamic process
{title2=$dS=\delta Q_{\rm rev}/T$}
A thermodynamically reversible process can be reversed without a net change of the system and surroundings. Its entropy change equals reversible heat transfer divided by temperature. A reversible <adiabatic process> conserves <entropy>; adiabaticity alone does not forbid internal entropy production in an irreversible evolution.