Resistivity And Electrical Conductivity

Every material acts as a conductor if it has a potential difference, i.e., a certain voltage is applied through its end, which leads to the flow of electric current through itself. Once the electricity is flowing through the conductor, the atomic structure of that material might alter the electric flow by opposing or resisting, and this property of the electric resistance between two points is termed resistivity. In contrast to this, some of the conductors have the property of electrical conductivity, also called specific conductance, which supports the flow of electric current through themselves. Therefore, resistivity and electrical conductivity are opposite or reciprocal to each other.

Electric Current

An electric current can be defined as the flow of electricity throughout a space, or a medium called an electrical conductor. The electricity flowing through a medium consists of electrically charged particles, such as electrons, ions, etc. These charged particles are also called the charge carrier. They particularly consist of some kind of charge over them, which is carried from one end to another due to the application of a voltage at the ends of the conductor. Therefore, the electric current measures the flow of electrically charged particles from one end to another end. Therefore, the electric current can be overall described as the flow of electric current through a medium or in a controlled volume atmosphere.

It is represented by the symbol “I.” Several fundamental derivatives are related to electric current, including resistance, resistivity, electrical conductivity, etc. The SI unit of electric current is Ampere, Also termed Colombo per second. The instrument used for measuring an electric current is called an ammeter.

Resistivity

Resistivity can be defined as the property of a material that opposes the flow of the electric current through itself, i.e., the electrical resistance between two points. The basic reason behind the material opposing this electric flow is their atoms’ structure and arrangement.

Some materials show high resistivity, whereas other materials show less resistivity. The SI unit of resistivity is ohm-metre, symbolically represented by . The terms resistivity and resistance are related to each other and perfectly described by Ohm’s Law. However, there are several factors that affect the resistivity of a conductor. The factors are:

1. The material of the conductor affects resistivity as each of the materials has a different atomic structure. Therefore, they have different capabilities for opposing the electric current.

2. Temperature is one of the greatest factors that affect the resistivity of a material. It is studied that with the increase or decrease in temperature, the material’s resistivity also alters its nature.

Ohm’s Law

According to Ohm’s Law, if an electric potential is applied through a conductor, the electric current starts flowing through it. This electric current is considered to be directly proportional to that of the voltage applied, i.e., the potential difference between the ends of the conductor. The mathematical expression of this proportionality can be written as,

V∝I

V=RI

Here, R is termed as the resistance.

It can be termed as the electrical resistance between two points. However, several factors affect the resistance, including the doubling the length and the cross-sectional area of the conductor. Therefore, the resistance can be expressed as,

R∝(L/A)

R= ρ(L/A)

From the given correlation, ρ is termed resistivity.

Therefore, it is clear that both resistance and resistivity are co-related to each other. They are directly proportional to each other, i.e., the increase in the resistance within a conductor will also increase the resistivity of that particular conductor material. Similarly, with the decrease in the conductivity within a conductor, there will be a decrease in the property of resistivity of the conductor material.

Electric Conductivity

Electric conductivity can be described as the property of the conductor, which supports the flow of electric current through itself. Some of the conductors have a unique atomic structure that causes more electric current to flow through them without any opposition or restrictions. Therefore, resistivity is termed as the opposite or reverse of electric conductivity. Therefore, the higher the resistivity, the lower will be the conductivity. Similarly, with the lower resistivity in the material, there will be a high property of conductivity. Mathematically the electric conductivity can be represented as.

σ=1/ρ

Here, denotes resistivity, and denotes electric conductivity.

The SI unit of electric conductivity is the inverse of resistivity. Therefore, it will be Ω^-1m^-1

However, it is also written as Siemens per metre or S/m.

Conclusion

The electric current is the flow of electrically charged particles through a conductor. However, some conductors oppose this electric flow causing an electrical resistance between two points, and some support the flow. The conductor that has the property of this resistance against the electric current flow is known as the conductor with the property of resistivity. On the other hand, conductors that have the property of supporting electric current are termed as the conductor with the property of electric conductivity. However, the terms electric conductivity and resistivity are inverse of each other.