One end of the tramline wire is at a constant voltage V relative to the ground.
At what distance from this end of the line is a tram equipped with two identical motors, and at what speed does it move, if the current in the line is I₁ when its motors are switched on in series, and I₂ when they are switched in parallel, and the speed of the tram does not change during such switching?
Friction force F, resistance of the wire length unit ρ, winding resistance of each motor R.
11.2 Vortex electric field