When by the provisions of this charter the council has authority to pass ordinances for any purpose, it may prescribe a penalty for each violation thereof. Such penalty shall be a fine or forfeiture of not exceeding the maximum allowed by state law, or imprisonment for a period not exceeding ninety (90) days or ninety-three (93) days in cases where state law so provides, or both, in the discretion of the court, together with payment of the costs of prosecution. Such ordinances may further provide that in case any person shall fail to pay any fine so imposed, together with the costs of prosecution, that he may be imprisoned until such fine and costs shall be paid. Provided, however, that no person shall be imprisoned for a single violation of any ordinance for a longer period than ninety (90) days or ninety-three (93) days in cases where state law so provides. Such penalty shall be prescribed in the ordinance.