Cross potential of a 4-arm network

This paper treats the loci of potential difference across the midpoints of a 4-arm network with constant coefficients and constant applied voltage. When the network is operated at constant frequency and any one of its arms varies along one of its components or at constant phase angle, the locus of potential difference is a circle. When the network arms remain fixed and the frequency is varied, the locus may or may not be a single circle and in many instances may be expressed as the sum of 2 circles or a circle and a bicircular quartic. To illustrate the practical application of this work, the analytical treatment and numerical results are given for typical networks.