Steady Current

Abstract

This chapter covers electric phenomena when there is a steady current flow. When a current is applied to a substance, an electric potential difference appears, and there is a proportional relationship between the current and the electric potential difference. This relationship is known as Ohm’s law on electric resistance. In this chapter, many examples of how to calculate resistance are shown. We learn also about the Joule loss that occurs when a current is applied to a substance with electric resistance. To realize a steady current in a closed circuit, we need an electric power source with an electromotive force. The fundamental principles on the behavior of electric circuits known as Kirchhoff’s law are given by the relationship between the electromotive force and the potential drop due to electric resistance, and by the fundamental feature of steady current.