Any ordinance or measure that the mayor and council, or the qualified electors of the city, shall have the authority to enact, the mayor and council may, of their own motion, submit to the electors for adoption or rejection, at a general or special municipal election, in the same manner, and with the same force and effect, as is provided in this chapter for ordinances or measures submitted on petition. At any special election called under the provisions of this Charter, there shall be no bar to the submission of other questions to a vote of the electors in addition to the ordinances or measures herein provided for, if said other questions are such as may legally be submitted at such election. If the provisions of two (2) or more measures approved or adopted at the same election conflict, then the measure receiving the highest affirmative vote shall control.