(a) The judges of the various city courts may preside in any of the city courts established by the General Assembly in the same manner as the superior court judges preside in the courts of one another; and any city court judge may exercise all the powers, duties, and functions devolved upon the judge of the city court over which he is called to preside by the request of the judge of such city court where the judge is disqualified or is providentially prevented from trying a case.
(b) Any judge of any city court in this state may preside and act in any other city court in this state upon the request of the regular judge thereof, and when so presiding and acting the judge shall have full power and authority over all matters pending in the court.