What is the relationship between Current and the Poynting Vector? In General Physics, I was stumped by the focus on the relationship between Voltage, Current and resistivity. It appears to me that Energy transfer should be the focus. But if this is true, what is the significance of current, and how are all of these terms related to one another? As usual, everything seems to be related to everything else.. I have yet to take anything higher than a bit of Calc II. It seems that diff eq. will be necessary if i wish to pursue topics like this, in any greater depth. Any thoughts regarding these things?