A steady current flows in a metallic conductor of non-uniform cross-section. The quantity/quantities constant along the length of the conductor is/are

If E be the electric field, then current densityj→=σE……….(1)We know that current density j = (i / A). So, j is different for different area of cross-sections. When j is different, then from eq. (1), E is also different. Thus E is not constant. The drift velocity vd is given byvd=j/ne=different for different j valuesHence only current i will be constant.