Question

explain how you can determine the direction of a magnetic field produced by a wire

Answer 1

the direction can be determined by the fleming right-hand grip rule: grip the conductor with your thumb pointing in the conventional current direction, and the curl of the fingers will represent the direction of the field. Alternatively, use the 'corkscrew rule' -the direction of the field is the direction you would turn a corkscrew when it points in the same direction as the conventional current. For electron flow (- to +), use the left-hand grip rule instead of the right hand.