Conventional and Electron FlowThe direction of electron flow is from a point of negative potential to a point of positivepotential. The direction of positive charges, or holes, is in the opposite direction of electronflow. This flow of positive charges is known as conventional flow. All of the electrical effectsof electron flow from negative to positive, or from a high potential to a lower potential, are thesame as those that would be created by flow of positive charges in the opposite direction;therefore, it is important to realize that both conventions are in use, and they are essentially equivalent. In this manual, the electron flow convention is used.PolaritiesAll voltages and currents have polarity as well as magnitude. In a series circuit, there is onlyone current, and its polarity is from the negative battery terminal through the rest of the circuitto the positive battery terminal. Voltage drops across loads also have polarities. The easiest wayto find these polarities is to use the direction of the electron current as a basis. Then, where theelectron current enters the load, the voltage is negative (Figure 31). This holds true regardlessof the number or type of loads in the circuit. The drop across the load is opposite to that of thesource. The voltage drops oppose the source voltage and reduce it for the other loads. This is because each load uses energy, leaving less energy for other loads.