The ratio of the rotating hysteresis loss to alternating hysteresis loss W_{r}/W_{h} is examined as a function of the magnetic field for various ferrimagnetic powders dispersed in a nonmagnetic matrix. A comparison of the W_{r}/W_{h} vs H behavior for single-domain particles with that of multidomain particles is made. The influence of the particle alignment in the matrix is also examined. The results obtained for the single-domain particle assemblies are explained on the basis of the "chain-of-spheres" model with fanning.