Does strip on wire mean negative or positive?

A strip of insulation removed from a wire typically indicates that the wire is a conductor, but does not inherently signify whether it is positive or negative. In many cases, particularly in DC circuits, the stripped wire may be used for the positive connection, but it ultimately depends on the specific wiring scheme and color coding used. Always refer to the wiring diagram or standard conventions for the specific application to determine which is positive or negative.