“Municipality” as used in this act means municipality as defined by Kan. Stat. Ann. § 10-101. “Utility” as used in this act means any instrumentality or facility of a revenue-producing character owned and operated by a municipality or operated for such municipality by a board of control or board of public utilities, as provided by law, for use in serving the public with water and electricity. “Revenue bonds” as used in this act means bonds issued by any municipality in this state to be paid exclusively from the revenue derived from the operation of such utility.