Topic :  Generalized Ohms law
see, e.g.  at http://theory.ipp.ac.cn/~yj/research_notes/mhd/node3.html

understand all the terms.  For example, in mechanics F = ma, so a force causes a mass to accelerate.  In E&M F is replaced by a voltage difference V.  So a V should cause the charges to accelerate, causing an increase in current with time, not a steady current.  This is not covered by the usual V = IR (or J = sigma E) Ohm;s law; it is the dJ/dt term in the generalized Ohms law.  When you add drag forces though (same as in PHYS 350), you can get a steady velocity (i.e., current).  Similarly explain the other terms and when they are or are not important.  This will require some research.