The Jiles-Atherthon model is suitable for modeling ferrite-core based inductors and transformers. In this paper it is used to quantify the influence of radially varying magnetizing field on induced voltage in a ferrite inductor, and to compare two conventional average models with a multi-segment model. To accurately model the core when its radial thickness is comparable with its average radius in which average models fail to work, multi-segmentation needs be adopted. In this paper quantification of required segments is presented for different ratios of outer to inner radii of a toroidal core. Such work is meaningful since the ferrite cores used in pulse transformers could be in the scale of meters and dimensional effect on induced voltage cannot be ignored.