The study of physical models within the framework of relativistic quantum mechanics in [Formula: see text] or [Formula: see text] space-time dimensions is often considered as a useful approach toward exploring real-world relativistic phenomena in [Formula: see text] space-time dimensions. This article presents the dynamics of a nucleon (which is either a neutron or a proton) with magnetic moment in the presence of certain electromagnetic fields in [Formula: see text] dimensions. In a polar coordinate, we examine four models described by the Dirac–Pauli equation: (i) neutron and proton harmonic oscillators; and (ii) neutron and proton hydrogen atom-like systems. We show that in some instances the energy eigenstates in noncentral potentials can be separable and exactly solvable. We present relativistic quantum-mechanical models of magnetic moments which can be further investigated.