Purpose <p>This work aims to examine the impact of porosity and inhomogeneity on an exponentially graded variable thickness rotating annular piezoelectric disc located in a magnetic field. The physical material properties are changed continuously as exponential law in radial direction taking into account the porosity factor and inhomogeneity parameter. The disc falls under the electromagnetic thermomechanical effect. The resulting differential equation is derived and contains Lorentz and inertial forces.</p> Methods <p>To solve the developing differential equations one can use the semi-analytical solution with the boundary conditions on the outer and inner surfaces.</p> Results <p>The outcomes were obtainable and the effect of the homogeneity parameter and the porosity factor were shown for special mathematical cases, and comparison was made between the porous and non-porous annular disc at dissimilar values of the inhomogeneity parameter and in multiple locations to see the effect on a complex engineering mathematical model.</p> Conclusion <p>The influence of inhomogeneity and porosity in the rotating hollow disk has a significant effect on all field quantities. Specific values for stresses and displacements are considered by choosing appropriate values of the inhomogeneity and porosity parameters. The outcomes can help in designing engineering mathematical models for such disks under various forces and boundary conditions.</p>