Conductors and their applications

While studying electrical current, it is essential to know about conductors. Materials exist in different forms; some might be excellent conductors, and others might not. But it is important to understand what makes an element an excellent conductor. Certain materials facilitate the flow of charge or electrons through them in various directions; this capability is basically what makes a material an electrical conductor. 

Depending on the capability of conducting electricity, materials are divided into conductors, superconductors and insulators. The knowledge of conductors helps in building electronic appliances and a lot more. 

What are conductors?

Conductors are basic materials capable of letting electricity flow freely through them. Other than that, heat also flows very easily through conductors. A good conductor enables a resistance-free path for a current mediating wire that passes through it. 

If we explain the overview of conductors, they basically possess free electrons on the surface, and these electrons allow the effortless flow of current through them. Electrical conductors facilitate the free flow of electrons between the atoms of the material. Metals are considered excellent conductors. Electrical conductors can be made of metals, metal alloys, certain non-metals (graphite, conductive polymers) and electrolytes. Metals are very commonly used electrical conductors because they possess high conductance and also low resistance.

How does current flow through an electrical conductor?

The atoms in an electrical conductor possess no energy gap between the conduction band and its valence band, and the electrons in the outer surface of the valence band stay loosely bound to the atom. When an electron reaches an excited state for the electromotive force of the thermal effect, it shifts from the valence band to its conduction band.

The conduction band is the place where the electron attains the liberation to move freely on the conductor surface. The conduction band is basically where the quantity of electrons is abundant.

In simpler words, we can say that metallic bonds are seen in the conductor, and these are built on the structure of the positive metal ions. Electron cloud surrounds these structures externally. 

When there is a potential difference at two points occurring in the conductor, the electrons gain enough energy to travel from the lower potential level to the higher potential level in the conduction zone, overcoming a small resistance created by the conductor material. The electrons here will flow against the flow of the electric current.

Properties of an electric conductor.

Some of the main properties of an electrical conductor are the following:

• Free movement of electrons or ions can happen in a conductor.
• The electric field present inside a conductor should be zero in order to let the electrons flow through the conductor effortlessly.
• The charge density present in the conductor is always zero, which means the positive and negative charges inside the conductor always cancels each other.
• Only free charges are found on the surface of the conductor because there are no charges present inside the conductor.
• The electric field working on the conductor is always perpendicular to the surface of the same conductor.

What are the different types of conductors?

Solid conductor: Metallic conductors –  copper, aluminium, gold, silver etc.

  Non-metallic conductors: Graphite etc.

  Alloy conductors: bronze, brass etc.

Liquid conductor: Metallic conductor – mercury.

    Non-metallic conductor: acid solutions, saline water etc.

Ohmic conductors: These are the conductors which obey Ohm’s law (V ∝ I). Example: silver, copper, aluminium etc.

Non-Ohmic conductors: These conductors never follow Ohm’s law, and the V vs I graph plotted will never give a straight line as well. Example: thermistors, bulb filament etc.

Metallic conductors: The majority of the conductors that we see are made of metals. An example is wires used in electronic appliances are mostly made of copper or alloys. The electric plugs that we use consist of metal, and also the conducting material inside possess metals. This is because there are innumerable free electrons in metals which promotes easy mobility to let the current flow.

The more the number of free electrons, the better the conductor. Of all the metals, copper and aluminium are the most widely used conductors, even though silver is the best conductor. This is because silver is expensive, and using it in simple electronic appliances will increase the prices; that’s why copper and aluminium is used.

Ionic conductors: any conductor in its solution form is called an ionic conductor. These fall under liquid conductors; saltwater is an excellent ionic conductor for electricity.

Magnesium, diboride, cuprate etc., are some of the best superconductors.

Conclusion.

We have discussed various aspects associated with conductors and the conductor’s importance in electricity flow in detail. Conductors play a quintessential role in making electrical appliances and also in carrying out experiments. It is incorporated in every little thing we use in our day to day lives, be it in the iron, electrical plugs or in our oven as well. 

Having a clear concept about the utility of conductor importance is essential to develop deeper knowledge about physics as well.