Electric current with respect to ground. Ohm's law states that the current through a conductor between two points is directly proportional to the potential difference across the two points. Introducing the constant of proportionality, the resistance, one arrives at the usual mathematical equation that describes this relationship: where "I" is the current through the conductor in units of amperes, "V" is the potential difference measured "across" the conductor in units of volts, and "R" is the resistance of the conductor in units of ohms. More specifically, Ohm's law states that the "R" in this relation is constant, independent of the current. In
Open-circuit voltage potential drop across the resistance C. The resistor B does not affect the open-circuit voltage. Since no current is flowing through it, there is no potential drop across it. So we can easily ignore it. Therefore, the potential drop across the resistance C is "V." This is just an example. Many other ways can be used. Open-circuit voltage Open-circuit voltage (abbreviated as OCV or V ) is the difference of electrical potential between two terminals of a device when disconnected from any circuit. There is no external load connected. No external electric current flows between the terminals. Alternatively, the open-circuit