What Is the Difference Between Resistivity & Conductivity?

What Is the Difference Between Resistivity & Conductivity
••• stoonn/iStock/GettyImages

Resistivity and conductivity are both properties of conductors. Conductors are substances that allow the flow of electrical current or thermal energy through them. The most common and well-known conductors of electrical current are metals. The most common and well-known conductors of thermal energy are metal and glass.

Resistivity

Resistivity is the electrical resistance of a conducting material per unit length. In other words, it is the degree to which a conductor opposes the flow of electricity through itself, instead allowing the energy to flow out of the electrical circuit, most often as heat. Resistivity is useful in comparing various materials based upon their ability to conduct electrical currents. The unit of resistance is the ohm.

Conductivity

Conductivity, by contrast, is the degree to which a conductor allows the flow of electricity through itself. The unit of conductivity is the siemens (S). It was formerly called the mho. Good conductors retain heat, minimizing the loss of energy from the electrical circuit. Copper wires, for example, are a material with excellent conductivity. Materials such as air, cloth, or rubber have very poor conductivity.

Relationship

Conductivity is resistivity’s reciprocal. A number and its reciprocal’s product is always 1. For example, the reciprocal of 4 is ¼. This means that as conductivity increases, resistivity decreases. Likewise, as conductivity decreases, resistivity increases. In practical terms, this means that a material cannot have high conductivity and high resistivity, but can have one or the other.

Uses

Conductivity has a myriad of uses. It determines what materials to make electrical parts from. It can also be used to test the purity of water (impure water conducts more readily). It can be used to sort materials by type as well. Resistivity has its uses as well. Of these, perhaps the best known is the use of rubber as an electrical insulator. Insulators are materials used to surround conductors to prevent the passage of electricity or heat out of the circuit.

Related Articles

What Are Insulators?
List Of Conductors
The Properties of Insulators
What Is a Ferrite Clamp?
How to Test a Blower Resistor
Similarities Between Conductors & Insulators
Properties of Thermal Insulators
Three Types of Conduction
An Electrical Engineer's Vocabulary Words
Factors Affecting Thermal Conductivity
How to Make a Simple Electric Conductivity Apparatus
Specific Conductance Vs. Conductivity
How to Calculate Conductance
How to Test Electrical Conductivity
The Uses of Electrical Conductors & Insulators
How to Convert 12 Volt to 6 Volt
Which Would Be the Best Insulator: Diamond, Gold, Lead...
How Do Thermistors Work?
Thermal Properties of Paper
Why Is Conductivity Important?

Dont Go!

We Have More Great Sciencing Articles!