Cyclic And Non Cyclic Process - Practice Questions & MCQ

Cyclic and Non-cyclic Process-

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

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

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

By applying first law of thermodynamics for cyclic process - 

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

For cyclic process, the initial point and final point is same. So, P-V graph is a closed curve and 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 second graph had done negative work

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