Choose the conditions for Reversibility are :
a) There must be complete absence of dissipative forces
b) The direct and reverse processes must take place infinitely slowly
c) The temperature of the system must not differ appreciably from its surroundings.
Reversible process must be a quasi static, very slow so that system is in thermo dynamical equilibrium in any intermediate stage. No loss of heat energy due to friction , viscosity etc. The net heat is not utilized in performing the net work.