The reason why I would like to use rectified AC is because I want to keep the magnetic field inside the coil unidirectional. A changing magnetic field induces current in the coil and vice versa. Although the current now flows in a single direction, its magnitude changes with time, it does not seem to me that using DC ripples would contradict Faraday's law.
- Hysteresis loss (this is now gone since the magnetic dipole moment won't spin due to the unidirectional field )
- Eddy current (this should still be here???....)
The unidirectional magnetic field is for alignment applications, I was wondering if I could get both heating and alignment at the same time without resorting to a mechanical switch that changes the AC source to a DC source. From the answers so far, it seems it is not recommended.