It seems to me that the typical relationship between
V, I and R is a relationship between scalars and, as such,
does not need a minus sign. Is this correct?
On the other hand, can we start with E = rho j (which is
a vector relationship) and replace E with - Del V,
rho = AR/L, and I = JA, to get a vector equation
with Del V, L, R and I? In that case, the vector
equation would necessarily have a minus sign, no?
____________________________________________
Robert Cohen; rcohen@po-box.esu.edu; 570-422-3428; http://www.esu.edu/~bbq
Physics, East Stroudsburg Univ., E. Stroudsburg, PA 18301