A theory of steady forces in variable-parameter networks

Passive linear reciprocal networks with elements dependent upon a generalized co-ordinate x are investigated in order to evaluate the steady component of the corresponding generalized force (Fx)av. Methods are found for expressing this force in terms of parameters measurable at the input terminals of the network. The analysis is particularly relevant to the absolute calibration of a class of square-law electrical measuring instruments, but the formalism is also applicable to other network systems where impedance is a useful concept.