The behaviors of bulk magnetoplasmon waves in a magnetized electron gas thin film in the Faraday configuration, as an example of an electric-gyrotropic film, are investigated. General expression for dispersion relation of the waves is obtained by two different approaches. Also, energy distribution and power flow of bulk and surface magnetoplasmon waves are studied. Furthermore, the group velocity and associated group delay time of bulk magnetoplasmon modes are obtained exactly by several different theoretical methods, such as the well-known wave theory method, the zig-zag ray approach based on the stationary-phase method and also the zig-zag ray approach based on the energy concepts. It is shown that the results are in completely consistent with each other.
