The north-south polarities of an electromagnet can be found easily by using:(a) Fleming's right-hand rule
(b) Fleming's left-hand rule
(c) Clock face rule
(d) Left-hand thumb rule

The north-south polarities of an electromagnet can be found easily by using the Clock face rule, because according to this rule "when an observer, finds the direction of current flowing in the anti-clockwise direction at one face of the coil, then the face of the coil will behave like the North Pole. While, if an observer, finds the direction of current flowing in the clockwise direction, then the face of the coil will behave like the South Pole".