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AlonsoMcLaren
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Homework Statement
http://physics.columbia.edu/files/physics/content/Quals2010Sec2.pdf
Problem 1
Consider a rigid, ideally conducting sphere of radius R, with total charge zero. The sphere rotates with angular velocity Ω, ΩR<<c. Suppose a dipole magnetic field threads the sphere. the dipole is centered.on the center of the sphere. The dipole moment μ is given and aligned with Ω.
(a) What voltage is induced between the equator and the poles of the sphere?
Homework Equations
Transformation of EM fields in special relativity?
The Attempt at a Solution
There is a solution on page 7 of the same document.
However, in (2) of this solution, the EM field transformation rules in special relativity are being used.
But the frame rotating with the sphere is non-inertial, can we still use these transformation rules?
If indeed, the EM field transformation rules are applicable to rotating frames, then I have a paradox:
Consider the notoriously painstaking problem of a rotating uniformly charged sphere, in which you are asked to find the magnetic field on the North Pole
The conventional solution to it is very nontrivial, the answer is B=2QΩ/5cR z^ (in Gaussian units)
But what if I do the EM field transformation trick? In the rotating frame, the electric field at North Pole is E'=Q/R2 z^ and there is no magnetic field. Since the North Pole is not rotating, the transformation rules just give B=B'=0... Contradiction...
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