A current through a horizontal powerline flows in east to west direction. What is the direction of magnetic field at a point directly below it and a point directly above it?

Explanation

The current is in the east-west direction. Applying the right-hand thumb rule, we get that the megnetic field (at any point below or above the wire) turns clockwise in a plane perpendicular to the wire. When viewed from the east end. and anti-clockwise. when viewed from the west end.