A constant current I flows in a horizontal wire in the plane of paper from east to west as shown in the following figure :

At which poit will the direction of the magnetic field be from north to south ?

Explanation

According to the Right -hand thumb rule , when a current -carrying wire is held in the right hand , with the stretched thumb from east to west in the direction of the current , the fingers wrapped around the wire be from north to south at the point lying directly below the wire .Hence, the magnetic field at that point would be from north to south .