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
Zero-ohm link 0805 size resistor of 0.003 ohms, rated at 1/2 watt can, in theory, safely pass up to 12.9 amperes of current. In practice, when approaching the power limit for a given package, it is good practice to either use an even lower-ohm product (more power-efficient but more expensive) or go up one package size larger (same power efficiency but cost may be kept lower). The "cost" associated with taking up more board space for the larger package may also be a consideration. In this example, for 12 amperes to pass through the jumper, a lower resistance or a bigger surface-mount