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   to 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

    1.

    2

    3

    4

    5

    6

    Conductors

    Silver

    Copper

    Aluminum

    Lead

    Tap water

    Gold

    Insulators

    Plastic

    Glass

    Bakelite

    Cotton

    Wood

    Cork

    S.No.

    7

    8

    9

    10

    11

    12

    Conductors

    Human body

    Living plant

    Brass

    Tin

    Iron

    steel

    Insulators

    Silk

    Pure water

    Rubber

    Leather

    Ebonite

    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 or bakelite. This saves you from getting electric shocks.

    Sample Questions
    (More Questions for each concept available in Login)
    Question : 1

    Gases are good conductors of electricity at ____________________

    Right Option : B
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    Explanation
    Question : 2

    In a metal,

    Right Option : D
    View Explanation
    Explanation
    Question : 3

    Which of the following is not a conductor of electricity?

    Right Option : C
    View Explanation
    Explanation
     
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