Cyclic And Non Cyclic Process - Practice Questions & MCQ

Cyclic and Non-cyclic Process-

Cyclic Process - A cyclic process consists of a series of changes that return the system back to its initial state.

Non-cyclic Process - In the non-cyclic process, the series of changes involved do not return the system back to its initial state.

Now, as we know that internal energy is the point function. So when the process returns to its initial point after completing the process then the final and initial internal energy will be the same. So, the change in internal energy is zero.

By applying the first law of thermodynamics for cyclic process - 

So, we can say that the heat given is equal to the work obtained in the cyclic process.

For the cyclic process, the initial point and final point is the same. So, the P-V graph is a closed curve and the area enclosed by the closed path gives the work done.

But, here is one assumption for the calculation of work done -

If the cycle is clockwise work done is positive and if the cycle is anticlockwise work done is negative.

From the given graph and its direction, you can see that the first graph is having positive work and the second graph had done negative work

Now, for the Non - cyclic process -  The work done is equal to the area covered between the curve and the volume axis on the P-V diagram. It does not depend on the points or state but it depends on the process of the path. We can see this in the given graph.