Best Answer: This is AC (Alternating Current) so it isn't positive and negative but hot and neutral. On a polarized plug, there is one wide blade and one narrow blade. The wide blade is neutral and the narrow blade is hot. The ribbed (white if there are colors) is neutral; the smooth wire (black if there are colors) is hot. So... hook the ribbed side to the wide blade (or white wire) and the smooth side to the narrow blade (or black wire). --------.