Some General Resonance Relations and a Discussion of Thevenin´s Theorem

It is shown that the maximum possible current which can be obtained through an impedance joining two points of a linear network is in general greater than the short-circuit current between those points; the maximum possible voltage is in general greater than the open-circuit voltage; the ratio of open-circuit voltage to short-circuit current is equal to the ratio of the maximum possible voltage to the maximum possible current, and both are equal to the magnitude of the input impedance of the network, etc. The condition for maximum voltage across a branch of a linear network is derived. As a preliminary, a form of Thevenin´s theorem different from the usual one and of greater usefulness in the analytical solution of some circuit problems is obtained.