FIG. 6.

(Color online). Comparison of the magnetic field components (B_y and B_z) and magnitude (|B|) due to an electrically active current dipole located at the origin and oriented along x̂ (first row), an electrically silent quadrupole ($a_{21}^2$, second row, see FIG. 1) and an electrically silent octupole (first configuration in FIG. 3, third row here). The physical parameters used are the same as in FIG. 4. Because the resultant dipole vectors from which the multipoles are composed are directed along x̂, the quantity B_x is identically equal to zero in the horizontal plane depicted and hence it is not displayed.