Statement (I): The Inequality of Clausius provides the criterion of the reversibility of a cycle.

Statement (II):  the cycle is irreversible and possible

Concept:

Entropy:

• Entropy is the index of unavailability or degradation of energy. Heat always flows from hot bodies to cold bodies and this becomes degrades or less available.
• For a reversible transfer of heat change in entropy

 where, s = entropy, Q = heat, T = temperature

• No process between two equilibrium states is possible if it would result in a decrease in the total entropy of the system and surroundings.

Clausius Inequality:

• Clausius inequality states that 
• It provides the criteria for the reversibility of a cycle.
• If , the cycle is reversible,
• If, , the cycle is irreversible and possible
• If , the cycle is impossible