Two concentric rings dielectrics and uniformly charged are suspended on the same floor.
The outer ring has a radius R and mass M, while the other has radius r << R and mass M.
The outer ring that has overall charge Q, is made to rotate around the axis passing through the center and perpendicular to the plane of the ring itself, with angular acceleration α.
Calculate the angular acceleration α' of thr inner ring.
My solution is the following:
The outer ring produce a variation of magnetic flux on the inner ring equal to
(μ * Q * π^2 * r^2 ) / ( α * R ) (*)
The inner ring produce a self-induced variation of magnetic flux for the law of Faraday-Lenz equal to
(μ * Q * π^2 * r' ) / α' (**)
Comparing the ( * ) and ( ** ), I obtain
α' = α * R / r
Is it my solution right?