Hello,
I have been discussing with a colleague of mine, in which cases of eddy current problems the electric scalar potential needs to be solved, additionally to the magnetic vector potential.
In this Paper, the author writes that sometimes it can be neglected and presents two eddy current examples. In one of the two examples it is ok to neglect 
. In the other one it's not. To me it seems (just a guess), that you have to solve for the electric scalar potential, as soon as there is any kind of open loop.
When browsing through the eddy current examples of the COMSOL Library, you can see, that this example is solved with the .mf physics module. In this module, only the magnetic vector potential is solved and (if I am right) no current conservation is used.
Does anybody know why it is ok to neglect the electric scalar potential in this specific example? Also, does the .mf physic check by itself if it has to use current conservation in a domain?
Greetings, Jan