Let's say there is a solenoid consisting of 8 loops. The Solenoid has an air core and the wire is welding wire. Each loop has a diameter of 1 Meter.

Now imagine a motor shaft running through the middle of the loops in the solenoid. Attached to the motor's shaft are 1 Tesla magnets that spin with the shaft. Each magnet has it's north pole facing towards the wire and it's south pole facing towards the center of the shaft.

IMPORTANT: Take note that the magnetic field covers the entire height of all eight loops (being that the loops are stacked on top of one another).

If one used 100 amp PULSED DC running through the wire and rotated the magnets on the shaft of the motor (the motor is not run on pulsed DC and is its own separate circuit) to a significant speed, WOULD THERE BE A LORENTZ FORCE ON ALL PARTS (dl) OF THE WIRE (on all eight loops).

In other words, would there be a Lorentz Force on 24 Meters of Wire?

I got 24 meters assuming that the circumference of each loop is around 3 meters.



If the wire had a net charge. Otherwise you will just experience eddy currents which will produce heat as in magnetic brakes in common use on trucks. It isn't going to produce currentm it's going to move the wire either up or down.

  • $\begingroup$ I gotcha. So if I had the pulsed DC at 60 Hz then there would be a force on the wire 60 times a second? $\endgroup$ – RyRy Dec 28 '16 at 0:37
  • $\begingroup$ Well DC is a moving charge, it would be cheaper to use a static charge - just connect it to the +V. With a moving charge it's more complicated,it creates it's own B-field, which will sum with the one from your mindblowingly massive 1Tesla magnets. $\endgroup$ – JMLCarter Dec 28 '16 at 0:40
  • $\begingroup$ Alright. The reason why I wanted to used pulsed DC is because I wanted to create a device that could achieve flight just by using the Lorentz force. If I used a static charge I think the hall effect would take place (correct me if I'm wrong). Can you please elaborate on what you meant by "which will SUM with the one..." what did you mean by "SUM". $\endgroup$ – RyRy Dec 28 '16 at 0:46
  • $\begingroup$ The hall effect is tiny, as I recall I wouldn't worry about it. By sum I mean vector addition. You can probably "fire" the ring of wire off the device. (You can't fly the entire device.) You don't need such a massive device. $\endgroup$ – JMLCarter Dec 28 '16 at 0:59
  • $\begingroup$ Or instead of spining the magnets, put DC into the wire. The charges in the DC current move around faster than you can spin a macroscopic object without it breaking. You don;t need to pulse the DC to get the effect. $\endgroup$ – JMLCarter Dec 28 '16 at 1:10

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