We have investigated two models of the third elementary electromagnetic dipole, known as the toroidal dipole. Its magnetic realization is a circumferentially magnetized ring constructed of neodymium. The electric model of the dipole is a toroidal coil connected to a DC voltage. The electric and magnetic toroids produce only an inner magnetic field, inside the torus, and interact only on contact with the electric current density or when immersed in a time-dependent electric field. We studied the characteristics of a permanent-magnet toroid, and observed the influence of electric and magnetic fields on it. A static toroidal dipole moment of this magnetic toroid was measured in interaction with the external current. In practical applications a magnetic toroid can be used as a magnetic field curl-meter or ammeter. The role of toroidal dipoles in particle physics and in technology is discussed.
Hanelli, A., Eshete, A., & Majewski, W. (2018). Physical Models of the Toroidal Dipole. Exigence, 2 (1). Retrieved from https://commons.vccs.edu/exigence/vol2/iss1/7