Animation shows a conductor moving in a magnetic field with its ends sliding on conducting rails. A resistance connected between the left ends of the rails provides a closed path for flow of current. The electrons riding with the conductor experierence forces directed along the length of the conductor which drive them around the circuit.
The force on a moving charge in a magnetic field is given by
When the conductor is moving to right and the magnetic field is directed outward this force on the electron is upwards and they circulate through the path provided by the rails in a counter clock wise sense. This constitutes a clock wise conventional current. As the direction of motion varies this force direction also varies.