It is NOT true to say that full employment or full-utlization of
resources will always be points on the PPC. A worker can be
employed but not being used efficiently will not produce the
maximum possible output eg a graduate is employed as a clerk.
Hence, when there is full employment of resouces but if the
resources are not used efficiently, it will only be a point inside
the PPC and but a point on the PPC.
The PPC is defined as a curve shows the maximum possible
combinations of output that can be produced when the country's resources are fully
employed and used efficiently at a given level of technology
at a given point of time.
A worker is a resource
So full employment of resources should also mean that the worker is
most efficiently employed. But you are right... I missed one word
out, which is efficiency. Efficient use of all resources should be
the phrase.
But then, these are all theoretical. In the real life, we know
this is not always possible.