When exposed to a potential difference, an electrical conductor is a material or substance that permits current to flow. This electric current will keep flowing until there is a potential difference. The density of electric current in a conductor indicates the efficiency of a conductor for a given potential difference. Low resistivity/high conductivity materials and high resistivity/low conductivity materials are the two types of conductors that can be classed based on their resistivity.

In the conduction band, electrical conductors allow electrons to move with a drift velocity between the atoms of a substance. Metals, metal alloys, electrolytes, and non-metallic materials such as graphite and conductive polymers are all examples of electrical conductors. Electricity can flow through these materials ( the flow of charge to pass through them easily).

The following are the basic characteristics of a conductor:

The conductor has the properties listed below when it is in an equilibrium state,

1. Resistance
2. Inductance
3. Inside the conductor, there is no electric field.
4. Inside the conductor, there is no charge density.
5. Only the conductor’s surface has a free charge.
6. The electric field is normal to the surface at the conductor surface.

A Conductor’s Charge Density is Zero

Under only electrostatic conditions, i.e. when charges are immobile, is the net electric field on the inside of the conductor zero. Free charges exist in a conductor and will always be travelling inside because an electric field exists. As a result, there must be no electric field inside a conductor for the charges to remain stationary. Not only that, but there are no net charges inside the conductor as well.

So, keep a conductor in a stationary external electric field. This field will appear instantly inside this conductor, and the random charges generated by it will move and rearrange in a matter of microseconds, producing an electric field that is exactly equal to and opposite to the external field, resulting in a net electric field inside the conductor of zero. The charges are stationary on the conductor’s outer surface.

If you have a time-varying electric field, on the other hand, the electric field exists and penetrates a small depth in the conductor. Skin depth is a term that refers to how deep your skin is.

Free charges occur only on the surface of the conductor

The field inside the conductor must be zero in electrostatic problems; otherwise, free electron charges will move under the influence of the field, and current will flow. Charges should, however, be stationary in electrostatics. This is why, when a charge is applied to a conductor, the charge is distributed so evenly that the field inside the conductor is zero. To achieve this, a charge is applied to the conductor’s outer surface, causing the surface to become equipotential, ensuring that current is zero even at the surface.

The movement of electrons and ions in them is permitted by a conductor

1. The free movement of electrons or ions is always possible in a conductor.
2. In order for electrons or ions to pass through a conductor, the electric field inside the conductor must be zero.
3. The charge density inside a conductor is zero, which means that the positive and negative charges cancel inside the conductor.
4. Because there is no charge inside the conductor, the conductor’s surface can only have free charges.
5. The electric field of such a conductor is perpendicular to its surface.

Conclusion

Electric conductors had a low resistance to electricity flow in general. An ideal conductor should have zero resistance. The resistivity of conductors, on the other hand, varies widely in practice. Low resistivity/high conductivity conductors are utilised in electrical machine winding, transmission lines, electrical contact, and earth wire, among other applications. For filaments in incandescent lamps and heating elements for electric heaters, ovens, and furnaces, conducting materials with a high resistivity/low conductivity are utilised.

One charged particle does not need to travel from the component creating the current (the current source) to those absorbing it in order for current to flow within a closed electrical circuit (the loads). However, the charged particle must just nudge its neighbour a finite number, who will then nudge their neighbour, etc until a particle gets pushed into the consumer, powering it. What is happening is a long chain of momentum transfer among mobile charge carriers; the Drude theory of conduction more precisely defines this process. This momentum transfer model makes metal a perfect conductor; metals have a delocalized sea of electrons, which allows the electrons to clash and cause a momentum transfer.