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

Appying Rihgt-Hand Thumb Rule as shown in figure, we find that the direction of magnetic field (B) at a point P directly above the powerline is from south to north whereas for a point `P^'` below it, magnetic field `(B^')` is from north to south.