What is electric current? The forces between objects that are rubbed in particular ways can be attributed to a property of matter known as charge (static electricity). Most textbooks assert that the electric currents through the wires connected to a battery are charges in motion. How do we know this? Perhaps current is something elseanother phenomenon. This is a question that received a great deal of attention from Michael Faraday, a famous early-nineteenth-century scientist. Faraday studied the effects of electricity from animals such as electric eels and tabulated his results in a table like the one shown in Figure 1-1. RTP3-1_06.jpg Figure 1-1: Reproduction of Faraday's table. The X's denote results obtained by Faraday and the 's denote positive results found by other investigators later. He concluded that, "electricity, whatever may be its source, is identical in its nature." The rate of flow of electric charge is more commonly called electric current. If charge flows through the cross section of a conductor in a time interval , then the average current can be expressed mathematically by the relationship: (in analogy to the definition of average velocity). Instantaneous current is defined as the charge per unit time passing through a particular