Conductors and Insulators

Concept Explanation

Conductors and Insulators

Conductors :

Conductors are materials or substances which allow electricity to flow through them. They conduct electricity because that have free electrons which can flow easily inside them from atom to atom. Also conductors allow the transmission of heat or light from one source to another.

Metals, humans, earth, animals are all conductors. The human body is a good conductor. So it provides a resistance- free path for the current to flow from wire to body. This is the reason we get electric shocks.

Conductors have free or valence electrons which allow current to pass through it easily.

Examples of conductors :

Materials such as silver is the best conductor of electricity. But, it is costly and so, we don't use silver in industries and transmission of electricity.

Copper. Brass, Steel, Gold and Aluminum are good conductors of electricity. We use them in electric circuits and systems in the form of wires.

Mercury is an excellent liquid conductor. Thus, this material find use in many instruments.

Gases are not good conductors of electricity because the atoms are quite far away. Thus, they are unable to conduct electrons.

Insulators :

These are the materials or substances which do not allow electricity to pass through them. This happens because they do not have free electrons to flow form one atom to other. These materials also do not allow the conduction of heat or light through them.

Plastic, glass, wood are some of the examples of insulators. This is the reason why electric wires are coated with plastic coating. PVC coating do not allow the electric current to leak into the surroundings.

Examples :

Glass is the best insulator as it has the highest resistivity.

Plastic is a good insulator and it finds its use in making a number of things.

Rubber is a common material used in making tyres, fire resistant clothes and slippers. This is because it is a very good insulator.

S.No

Conductors

Silver

Copper

Aluminum

Lead

Tap water

Gold

Insulators

Plastic

Glass

Jute

Cotton

Wood

Cork

S.No.

Conductors

Human body

Living plant

Brass

Tin

Iron

Steel

Insulators

Silk

Pure water

Rubber

Leather

Paper

Nylon

Both conductors and insulators are important in using electricity. Whenever we want to make a circuit to use electric current in some way, for example, to light a bulb, run a fan, work an oven or run a washing machine,we use wires made of a metal, such as copper or aluminium, which are good conductors. However, we cannot use bare wires as this would be dangerous. A bare wire carrying current can give you an electric shock. Therefore, wires are always coated with an insulating material, such as plastic. You would also have noticed that the outer coverings of switches, regulators of fans, plugs, sockets, etc. are made of an insulating material, such as plastic. This saves you from getting electric shocks.

Sample Questions

(More Questions for each concept available in Login)

Question : 1

When electric current flews through a conductor, the conductor becomes
A. liquid	B. vapour	C. hot	D. cold
Right Option : C
View Explanation

Question : 2

Electrical wires are made from copper and silver because copper is ________________
A. better conductor	B. better insulator	C. less expensive	D. non magnetic
Right Option : C
View Explanation

Question : 3

Insulators _________________
A. Conduct electricity		B. Do not conduct electricity
C. Conduct electricity only at low temperatures		D. Conduct electricity at room temperatures
Right Option : B
View Explanation