I have a question regarding the AC circuit shown below. If we ignore the voltage drop caused by the long cable, I think the device will work and the circuit can be considered as a closed circuit.
![enter image description here][1]


  [1]: https://i.sstatic.net/L52w5.png

Now I am wondering about how the electrons can return back to the source to form a closed path and so a closed circuit!?

As it appears, there are 1000 of Kilometers between GND1 and GND2, or we can say that there is infinite value of ohms (resistance) between the two grounds. So, where is the closed path for the electrons flowing?