Using one of maxwell's equations in integral form

integral(B*dl) = mu_0*epsilon_0 integral(dE/dt * da)

Apply the bounds for dl as 0 to 2 pi and for da as 0 to R and 0 to 2pi.

After integrating, you find the integral on both sides after applying the derivative with respect to time of the Electric field.

Understanding that dipole moments (Mu), magnetic field (B), and current (I), are proportional to current (I), velocity of the electron velocity (v), and v, respectively you should be able to find relation between the magnetic dipole moment and magnetic field of the electron to many constants. However, now you simply want to take the delta of both of them to give you a change of them.

Keep in mind, you should have the constants q, N, A, and m in your final expression.

Yes, they would if the earth acted as a giant dipole then it would be true for every point outside of the Earth's dipole moment range.