The brief expression of Ohm's law is that in the same circuit, the current passing through a conductor is directly proportional to the voltage across the conductor and inversely proportional to the resistance of the conductor. The law was written by a German physicist? Georg simon ohm's paper "Determination of Metal Conductivity Law" was published in April 1826. With the development of circuit research, people gradually realize the importance of ohm's law, and ohm's reputation is greatly improved. In memory of Ohm, right? With the contribution of electromagnetism, the unit of resistance is named ohm in physics, which is represented by the symbol ω.

I is current, u is voltage and r is resistance. Resistance r = u/i.