Magnetic fields in moving conductors: four simple examples

Assuming given externally applied magnetic fields and given velocities, we calculate the currents induced in moving conductors of arbitrary conductivity, and the net magnetic field. Three of the four conductors are solid, and the fourth is fluid. We find that, in these examples, the net magnetic field is either unaffected by the moving conductor, or distorted downstream, or distorted upstream. In all cases the net magnetic field is static.