# What is the Difference Between an Ohmic and Non-Ohmic Conductor?

## Answer #1

Level 2 (suitable for students)

Answered by Alexander Fufaev

**Ohmic conductors** are characterized by the fact that the set voltage \(U\) on the ohmic conductor is proportional to the electric current \(I\), where the proportionality constant is the electric resistance \(R\):

**Ohm's law applies to ohmic conductors**

Formula anchor $$ \begin{align} U = R \, I, ~~~ R = \text{const.} \end{align} $$

If the voltage \(U\) is doubled, then the current \(I\) through the conductor is also doubled.

**Non-Ohmic conductors**, on the other hand, are all conductors that do not satisfy Ohm's law 1

. This means that the doubling of the voltage \(U\) does not have to result in the doubling of the current \(I\). In illustration 2, the U-I graphs of non-ohmic conductors are sketched as examples: Transistor graph (1), gas discharge graph (2) and diode graph (3).