The piezoinductive effect in a ferroelectric ring with nonmagnetic conductive electrodes on its inner and outer surfaces and subjected to a dc bias magnetic field is discussed. The effect results from combination of the electromagnetic induction in the conductive loop and the piezoelectric effect in ferroelectrics. A theory for the direct and converse piezoinductive effects is developed. Data on piezoinductive voltage when a ring of lead zirconate titanate (PZT) is subjected an ac magnetic field h and a dc bias H show a linear increase in both h and H and a resonance enhancement at electromechanical resonance. Similarly the ac magnetic field generated by PZT due to the converse piezoinductive effect when the sample is dc biased and excited with an ac voltage U shows a linear dependence on U and H. The theory and data are in very good agreement. The effects discussed here are of importance for magnetic field sensing and modulation. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3195073]