Electrons' Motion in an electromagnet is on the order of 10 − 4 m/s. That charge can be mechanically rotated in a capacitor with a million times more velocity (B produced being proportional to charge's velocity ).Forces causing eddy currents would help to negate net magnetic field in an ordinary capacitor. However, if radially oriented, unidirectionally conducting (" chair " ) carbon nanotubes are rotated, the electrons would be relatively constrained from eddy currents.It seems like this would allow greater magnetic field production compared to standard electromagnets.

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Electrons&#039; Motion in an electromagnet is on the order of       10          −      4       m/s. That charge can be mechanically rotated in a capacitor with a million times more velocity (B produced being proportional to charge&#039;s velocity ).Forces causing eddy currents would help to negate net magnetic field in an ordinary capacitor. However, if radially oriented, unidirectionally conducting (&quot; chair &quot; ) carbon nanotubes are rotated, the electrons would be relatively constrained from eddy currents.It seems like this would allow greater magnetic field production compared to standard electromagnets.

uavklarajo · Accepted Answer

Say we have a little electromagnet maybe   5 cm long with   100 loops of wire and we run   0.25 A of current through it. With an air core we should get a magnetic field inside or about   1 millitesla.Now, what if we wanted to do that with a rotating static charge? You are proposing moving it a million times faster than       10          −      4       m/s so   100 m/s.In our solenoid we are using the same current   100 times to produce the magnetic field, effectively it&#039;s like a   25 A current going around a loop once. We need to get the equivalent of a   25 amp current by swinging some charges around. Current is the rate of charge flow,   I  =  q      /    Δ  t, so we need to estimate   Δ  t which will depend on the radius or rotation - let&#039;s say, arbitrarily, 1 cm. So,   Δ  d  ≃  6 cm which gives   Δ  t  ≃  6  ×      10          −      4       s. And, when we solve for q we get   0.015 coulombs. This is not a small amount of static charge to produce a modest magnetic field. (Remember those van de Graaff generators from physics class that made your hair stand up - that had a charge in the order of   0.000  005     C  .) And that, I think, is where your problem is going to be.

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