Ordinances and resolutions providing for current expenses of the Municipality, or for public improvements petitioned by the owners of a majority of the foot frontage of property benefited and to be specially assessed for the cost thereof, or for raising revenue, or ordinances and resolutions wherein an emergency is declared to exist, shall become effective immediately upon passage or at such later date as may be provided therein. All other ordinances and resolutions shall take effect thirty (30) days after passage. An emergency ordinance and resolution as referred to herein is one which must be passed and made effective at once or in less than thirty (30) days to meet an emergency in the operation of the City government, or which is necessary for the immediate preservation of the public peace, health, safety, or welfare. Each emergency ordinance or resolution must contain therein a separate section setting forth the reason for the emergency. No ordinance or resolution granting a franchise, or for zoning, or fixing a rate to be charged for a public utility shall be passed as an emergency measure.