Remember that a current-carrying conductor produces a magnetic field around it. If the current direction is reversed, the magnetic field direction will be reversed too, as shown in the diagram above. A dot in the wire, as shown above, shows the current coming out of the plane whereas a cross in the wire shows the current moving into the plane. Grip the wire with your right hand in such a way that the thumb is pointing to the direction of the current. The curl of your fingers, in turn, will show the direction of the magnetic field. The strength of the magnetic field in a long, straight current carrying wire depends on the magnitude of the current. A larger current will produce a stronger magnetic field around the wire. the distance from the wire. The strength of the field decreases as you move further out. The direction of the field can be determined by the right hand grip rule.