The Helmholtz rule states that the direction of the magnetic field produced by a current-carrying conductor is given by the direction of the current itself. In...
The Helmholtz rule states that the direction of the magnetic field produced by a current-carrying conductor is given by the direction of the current itself. In other words, the magnetic field lines around a current-carrying conductor point in the same direction as the direction of the current. This rule can be explained by considering the behavior of a positive charge moving in a magnetic field. According to the right-hand rule for electric fields, the direction of the electric field is determined by the direction of the motion of a positive charge. Since a current is a flow of electric charges, the direction of the magnetic field is determined by the direction of the motion of the charges that make up the current