Your experiment has undefined behavior as soon as you dereference the pointer after the delete statement. Everything can happen, which makes your experiment rather worthless.
What does delete (not delete[]) do? It deallocates the storage pointed to by its argument. This will trigger the destructor of the object stored at that location to be run. Accessing storage that has been deleted triggers undefined behavior (often a segmentation fault). There are no guarantees that the memory is actually handed back to the operating system or anything else.
