George inserts a long straight wire running from south to north in a circuit. The

George inserts a long straight wire running from south to north in a circuit. The direction of the conventional current is also from south to north. a. What is the direction of magnetic field of this current-carrying wire? b. What happens to the direction of magnetic field if the direction of flow of the conventional current is reversed? c. Name the rule used in solving parts a and b of this question.