A city of the primary class may borrow money on the credit of the city and pledge the credit, revenue, and public property of the city for the payment thereof when authorized in the manner provided by the home rule charter of the city or as otherwise provided by law. Such city shall have the power to issue general obligation bonds of the city, general obligation notes, and refunding bonds, as provided in its home rule charter or as otherwise provided by law. Such city shall have the power to issue revenue bonds for the purpose of acquiring, constructing, reconstructing, improving, extending, equipping, or furnishing any revenue-producing facility within or without the city which is for a public purpose, except that unless authorized by a majority of the voters of such city voting upon the question, no revenue bonds shall be issued for entering the public transportation, natural gas distribution, or telephone fields or functions. Such city shall also have the power to contract for the acquisition of the electric facilities and properties used or useful in connection therewith of a public power district within or without the city and to pay for all or any part of the acquisition out of the earnings of electric facilities and properties.