Ohm's law
![V, I, and R, the parameters of Ohm's law.](/Images/godic/202501/30/OhmsLaw.svg3234.png")
![Georg Ohm](/Images/godic/202501/30/Ohm33234.gif")
![Ohm's law in Georg Ohm's lab book.](/Images/godic/202501/30/Ohmsches_Gesetz_in_Georg_Simon_Ohms_Laborbuch3234.jpg")
![Drude Model electrons (shown here in blue) constantly bounce among heavier, stationary crystal ions (shown in red).](/Images/godic/202501/30/Electrona_in_crystallo_fluentia.svg3234.png")
Ohm's law states that the current through a conductor between two points is directly proportional to the voltage across the two points. Introducing the constant of proportionality, the resistance, one arrives at the usual mathematical equation that describes this relationship: