Ohmic & Non-Ohmic Conductors Not all conductors and electronic components follow the ideal Ohms law characteristic of a linear relationship between voltage and current. There are many examples of Ohmic conductors and non-Ohmic ones.

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Ohms Law states that there is a linear relationship between voltage and current. Conductors and electronic components that follow this law are called Ohmic conductors, whereas others are called non-Ohmic conductors

The Ohmic conductors may also be called linear electronic components, whereas the others are non-linear as they do not have a linear relationship between voltage and current.

In understanding the basics of electronics as well as many elements of electrical science it is necessary to understand why some electronic components and conductors are Ohmic following Ohms law and others are non-Ohmic having a non-linear relationship between voltage and current.

There are very many examples of both Ohmic and non-Ohmic conductors. Both types are widely used in all forms of electrical and electronic components and systems.

Video: Discovering Ohmic & Non Ohmic Conductors

In view of the importance to electrical design as well as electronic circuit design, it is important to understand which conductors as well as which electronic components fall into which categories.

Looking at Ohmic conductors it is worth giving a more precise definition of what they are:

Ohmic conductors definition:

Ohmic conductors are those electrical conductors that follow Ohms law. In other words there is a linear relationship between voltage and current for all values

In view of the Ohmic conductors definition it means that if the voltage across the conductor, electronic component, etc is doubled, then the current will also double.

Very broadly speaking items made from metals, carbon, and many metal alloys fall into the Ohmic conductors category.

The relationship between the voltage current and resistance follows Ohms law - it is linear and can be calculated using Ohms Law.

V = I R

Some of the main examples of ohmic conductors and electronic components include:

These are but a few examples of Ohmic conductors and devices. Ohmic conductors and electronic components are the most straightforward of items. They simply obey Ohm's law and operate in a linear fashion where V = I ⋅ R.

There is a surprising number of electrical and electronic components that are non-ohmic. Essentially they exhibit a value of resistance that varies with the voltage applied.

Again it is worth defining what a non-Ohmic conductor or electronic component is:

Non-Ohmic conductors definition:

Non-Ohmic conductors are those electrical conductors that do not follow Ohms law. In other words the relationship between voltage and current is not linear for all values

In other words doubling the voltage will not result in a doubling of the current. This can occur for a variety of reasons dependent upon the actual conductor or component in question.

Some of the main examples of non-ohmic conductors and electronic components include:

These are just three examples of non-Ohmic conductors and components. There are various other types which can be encountered. Varistors are but one example. These are used for protecting against mains power or line transients. Normally they have a high resistance, but when a certain voltage is exceeded, the resistance falls so that they absorb the transient and protect the units being powered.

Ohmic and non-Ohmic conductors as well as electrical and electronic components are found in all areas of electrical and electronic science. Both types of conductor are used, and their individual properties are put to specific uses to provide the wealth of capabilities that are needed to support modern day electrical and electronic circuit design, components, and systems. It is surprising what a variety of ways in which these different characteristics can be used.

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