Properties of a conductor

Introduction:

 Conductors are materials that contain moving charges. In conductors, electrons are movable charged particles. Due to these freely movable electrons, conductors conduct electricity easily. The common electrical conductors are metals. All conductors contain a charge that moves when a potential difference (measured in volts) is applied to various points in the material. This charge flow (measured in amperes) is called current. For most materials, the current is proportional to voltage as long as the temperature is kept constant and the material maintains the same shape and condition.

Properties of conductors

 There are various properties of a conductor which are listed below:

Resistance of conductor 

In an ideal condition, the value of resistance in a perfect conductor is zero. But in practical conditions, its value varies from low to high. Low resistivity/high conductivity conductors are employed in the winding of electrical machinery, transmission lines, electrical contact and earth wire, among other applications. For filaments in incandescent lamps and heating components for electric heaters, ovens and furnaces, conducting materials with high resistivity/low conductivity is employed.

Inductance of conductor

When an AC supply is connected to the conductor, flux linkage comes into the picture. Due to this, an inductance comes into the picture which is responsible for the non-uniform distribution of current over the cross-section area of the conductor. Furthermore, this inductance affects the current distribution across the conductor’s cross-section area. As a result, the current prefers to flow through the cross-sectional area’s outer part. This is known as the Skin Effect. The flux connection to the conductor, which is caused by the current flowing through the neighboring conductor, also affects the current distribution throughout the cross-sectional area. This is known as the Proximity effect. Both of these effects, the skin effect and the proximity effect, are only present when using AC power.

The behavior of the electric field

Inside the perfect conductor, the electric field is zero. An electric field exists only outside the surface of a conductor. If an electric field exists inside a conductor, it exerts a force on electrons, causing them to accelerate. However, in equilibrium, the net force on the electron is zero. As a result, there is no electric field inside the conductor. This property of the conductor makes it reasonable to be utilized for electrostatic protection for electrical hardware.

The charge density of the conductor

Due to the electrostatic repulsion force, inside the conductor, there is no electric charge which results in zero charge density inside the conductor. Because of the mutual electrostatic repulsion force between like charges, such as electrons, the electrons must be as far apart as feasible.

Existence of free charge

The free electric charge exists only on the outside surface of the conductor. There is no charge inside the conductor. Electrons travel to the conductor’s outer surface due to electrostatic repulsion. As a result, there is no electric charge within the conductor. As a result, free electric charge only departs the conductor’s surface.

The electric field at the conductor surface

In a conductor, the electric field is perpendicular to the surface of the conductor and zero when it is tangent to the surface of the conductor. The electric field intensity is perpendicular to the conductor’s surface and the tangential component of the electric field intensity is zero.

Conclusion

Based on the above discussion, we conclude that the conductors are a good carrier of electric current. The human body, metals like copper, silver, aluminum, etc., all are good conductors of electricity. All conductors exhibit various properties that define the characteristic behavior of a perfect conductor. In an ideal conductor, the value of resistance is zero. Hence a conductor should have low resistivity and high conductivity. There are various elements as discussed above which are the good conductors of electricity. But, if we look at economical aspects, copper and aluminum are best suited for daily use like in transmission lines, cables and in other electrical types of equipment.