we know i = dq/qt = enLA/dt = en(Vd)(A) standard derivation i en(Vd)(A) where e is charge on electron n is electrons per unit vol. Vd is drift velocity of electrons A is area of cross section of conductor SO my doubt is if we have a conical conductor or some kind of conductor whose CSA is not constant , will we have variable current across its length according to i = en(Vd)A I also want to ask what is current density ?? Precisely i want to know - current density(j) = di/dA here what is ''di'' signifying ???