Mechanical Engineering - Thermodynamics - Discussion

Please I don't understand can you justify more please.

In the constant pressure process only pressure remains same in both the states and other parameters change. So obviously it is not a reversible process. Similar for all the cases.

I also agree all the above process is reversible.

Reversible process is one in which path of the process is known. And when equation for a process is defined that means path is also defined. So answer is false they all are reversible process.

False is correct. Because there is constant pressure process, it means pressure at state point 1 is equal to pressure at state point 2. So there is no energy loss. Similarly this concept is applicable to constant volume process also. So it is reversible process.

Is that these processes can not back their initial stage then which process get back their initial stage.

In reversible process initial states to final states and can be back to initial. And these process do not came in initial state.

Then these process is irreversible process.

Answer is wrong. It is also reversible process. So false is correct answer.

1) In the irreversible process the initial state of the system and surroundings cannot be restored from the final state.

2) During the irreversible process the various states of the system on the path of change from initial state to final state are not in equilibrium with each other.

3) During the irreversible process the entropy of the system increases decisively and it cannot be reduced back to its initial value.

4) The phenomenon of a system undergoing irreversible process is called as irreversibility.

How we can say that all of above is irreversible process? please tell me.