Chapter 6 Second-order circuits In the chapter we shall study the properties of second-order circuits, 1. e, circuits containing two energy-storage elements. Such circuits will in general, be characterized by second-order dififerential equationsChapter 6 Second-order circuits In the chapter we shall study the properties of second-order circuits, i.e., circuits containing two energy-storage elements. Such circuits will, in general, be characterized by second-order differential equations