A constant current flows in a horizontal wire in the plane of the paper from east to west as shown in the figure. The direction of the magnetic field will be north to south at a point:

Quick Oral Answer

The direction of the magnetic field can be determined using the right-hand thumb rule. According to this rule, if we point our thumb in the direction of the current, our fingers will wrap around the conductor in the direction of the magnetic field. In this case, the current is flowing from east to west, so the magnetic field will be directed from north to south at a point directly below the wire.