# work done in reversible and irreversible process

According to maximum work theorem work done maximum work is done during reversible process . consider a reversible adiabatic and irreversible adiabatic process that occurs between two states of the system. Now work done in an irreversible adiabatic process is less. Change in internal energy is same for both the process. No heat is exchanged in both the process , since the process is adiabatic. Doesn't this violate 1st law?

• I added an example to my answer to illustrate what I'm saying. – Chet Miller Feb 9 '16 at 16:32

State 1: One cube at $T_h$ and the other at $T_c$
State 2: Both cubes at $(T_h+T_c)/2$