In this blog, you will learn what are conductors and insulators, their everyday uses and examples.
What is Conductor?
Materials that allow electrons to flow through them freely from one particle to another are conductors or Conducting materials. The charge gets distributed on the entire surface of the material due to electron movement. Conductors are typically made of metals. However, there are some non-metallic conductors such as graphite in the pencil and salt solutions.
Examples of conductors are Silver, gold, copper, iron, brass, steel, mercury, graphite, dirty water, aluminum, human body, and aqueous solution.
What is an Insulator?
Materials that do not allow electricity to pass through them or stop the free flow of electrons from one particle to another.
Examples of insulators are:- glass, rubber, dry paper, dry cotton, cork, wood, plastic, oil, porcelain, ceramic, polythene, wool, nylon, bakelite. Perfect vacuum and pure water are also examples of excellent insulators.
Why do we use only metal wires for making electric circuits? Let us find suitable materials that can be used for connecting different electrical components in an electric circuit. The material should be such that it allows the electric current to pass through it.
Difference Between Conductors and Insulators
|1.||Materials that allow free flow of electricity are known as Conductors.||Materials that stop free flow of electricity are known as Inductors.|
|2.||Electrical resistance is very low.||Electrical resistance is very high.|
|3.||Conductors contain a large no. of electrons.||Insulators don’t have free electrons.|
|4.||Example- Copper & Aluminium||Example- Paper & Wood|
|5.||Most metals are conductors||Most Nonmetals are Insulators|
Let’s do an Activity:-
- Take a pencil cell and attach the wire to its positive and negative terminals. Now take a torch bulb and attach wires to its metal case and metal tip at the base.
- Connect any terminal of the bulb to either the positive or negative terminal of the cell. Now you have two free ends of the wires. Bring the free ends of the wires in contact with each other. What do you observe? The torch bulb lights up.
- Now we are going to use this set-up to find out whether a given material allows electric current to pass through it or not. You can call this set up a continuity tester.
- To test a material, free ends of the wires are brought in contact with the ends of the material. We note down whether the bulb glows or not.
- Now we test one by one material such as cork, rubber, keys, glass, all pins, scale, pencil lead, wooden block, aluminum foil, sewing needle, thermocol, steel spoon, coin.
- Does the bulb glow in each case? We find that the bulb did not glow in the case of cork, rubber, glass, plastic scale, wooden block, and thermocol. This means that these materials do not allow electricity to pass through them. On the other hand, the key, all pins, pencil lead, aluminum foil, sewing needle, steel spoon, and coin allowed the electricity to pass through them. Materials like cork, glasses, etc, which do not allow electricity to pass through them, are called INSULATORS. And the materials like pencil lead, aluminum, etc which allow electricity to pass through them are called CONDUCTORS OF ELECTRICITY.
The brighter the bulb glows, the better the conductor of electricity is.
Let’s learn various uses of conductors and insulators:
Uses of Conductors
- Conductors, such as copper, aluminum are used for making electric wires.
- Switches, electric plugs, sockets, bulb holders are made of copper or brass.
- Filaments of bulbs, elements of heating devices such as electric irons, geysers, and room heaters are made of conductors.
Uses of Insulators
- Insulators are used for separating electricity from objects and living things.
- Power lines are separated from the metal towers by a stack of ceramic insulators.
- Conducting wires and power cords are covered with flexible insulating plastic so that we can safely touch a plugged-in cord.
- Insulating tapes are used by an electrician to cover the naked ends and joints of electric wires
- Bakelite, an insulator is used to cover plug tops and switches
- Insulators protect an electric circuit from coming in contact with conducting objects that could damage the circuits.
- Insulators protect people and animals from coming in contact with live wires that could be harmful.
- Our body is a conductor of electricity. Therefore, we should be careful when handling electrical appliances.
- Electric irons, refrigerators, microwaves, electric toasters are provided with plastic handles to protect us from getting any shock from the bodies of these appliances.