Schematic view of an unipolar inductor. In a pulsar wind, the unperturbed wind’s magnetic field B₀ and velocity v₀ are almost, but not exactly, perpendicular. The electric field E₀ created by the unipolar inductor is perpendicular to these two vectors; it induces an electric current (of density j) along the body. This current then escapes into the surrounding plasma, forming two structures, each of them consisting of an outwards and an inwards current flow. The current density j flowing along the body causes a j × B force density to be exerted on it.