From powering large machinery to lighting our houses, electricity is essential for our daily life. However, have we ever thought over why certain materials give the passage to electricity while others entirely obstruct it? Conductors and insulators are useful in this situation.
What are Conductors?
Materials that readily permit electric current to flow through them are known as conductors. This is due to the fact that they contain free electrons, sometimes called as conduction electrons, which are able to freely travel throughout the material. By transporting electrical energy from one location to another, these electrons function as messengers.
Examples of Conductors:
Metals like copper, silver, aluminum, and gold
Human body (because of the water and salts in it)
Saltwater
Graphite (a form of carbon)
Why Metals Conduct Electricity:
The valence electrons, which are the outermost electrons of atoms in metals, are weakly bonded and free to move. These electrons wander in a specific direction when an electric field is applied, producing an electric current.
What are Insulators?
Materials known as insulators make it difficult for electric current to flow through them. There are no free electrons accessible to conduct electricity since their electrons are firmly bonded to their atoms.
Examples of Insulators:
Rubber
Plastic
Glass
Wood (especially dry wood)
Pure water (note: impure water can conduct electricity)
Insulators are used to protect us from electric shocks and to cover wires and cables to ensure safety.
Differences Between Conductors and Insulators:
Property | Conductors | Insulators |
Electron movement | Free electrons move easily | Electrons are tightly bound |
Electrical resistance | Low | High |
Heat conduction | Usually good conductors of heat too | Poor conductors of heat |
Use | Wiring, electrical circuits | Insulation, safety gear |
Examples | Copper, silver | Rubber, plastic |
Important Points:
When some charge id transferred to a conductors, it get distributed over the entire surface of the conductors. While in case of insulators, the charge stays at same place.
The phenomena in which we bring a charged body in contact with the Earth ar ground and all the excess charge on the charge body leaks to the Earth is called earthing. Earthing provides a safety measure for all electrical circuit and appliances.
There are three wires in electric wiring of our houses; live, neutral and earth. The live and neutral wires are used to carry electric current from the power station and earth wire is connected to the earth. Metallic bodies of the electric appliances are connected to the earth wire which carries extra charge to the ground.
Applications in Daily Life:
• To facilitate the easy passage of electricity, wires are composed of conductors like copper or aluminum.
• To stop shocks and short circuits, wire coatings are composed of rubber or plastic (insulators).
To regulate the flow of electricity, circuit boards combine insulators (like fiberglass) and conductors (like copper rails).
• Air serves as an insulator between the ground and high-voltage cables in power lines.
Conductors and Insulators in Electrostatics:
In electrostatics, conductors and insulators behave differently:
In a conductor, charges move freely and spread out evenly over the surface.
In an insulator, charges stay in the area where they are placed, since they can’t move through the material.