Tag: conduction
Questions Related to conduction
Easy to shape materials like ceramics are used as
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conductors.
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insulators.
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electrodes.
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catalysts.
Overhead cables are insulated from pylons through
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plastic.
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ceramics and glass.
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rubber.
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PVC.
In conductors outer electrons :
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are not tightly bound to the nucleus
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are tightly bound to the nucleus
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never becomes free electrons
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are always free to move
Conductors can easily conduct electricity because they are loosely bound to the nucleus and they are not engaged in chemical bonding. Conductors have free electrons.
In conductors, electrons can flow because their
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ions are free
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protons are free
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electrons are free and mobile
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negative ions are free
In conductors, electrons can flow because their electrons are free and mobile metals have free electrons present in outermost orbit i.e. they are mobile in nature. This is the fact due to which they could produce electricity.
An insulator is a non-metallic substance which :
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allows heat to pass through it
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has extremely low resistance to the flow of charge through them
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has extremely high resistance to the flow of charge through them
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increases current in the circuit
An electrical insulator is a material whose internal electric charges do not flow freely because of extremely high resistance. Very little electric current will flow through it under the influence of an electric field.
Metals are good conductors of electricity than non-metals because:
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Metals have free electrons which can move from atom to atom easily
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Non-metals have free electrons which can move from atom to atom easily
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Metals have bound electrons which cannot move easily
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Non-metals have bound electrons which cannot move easily
Metals have free electrons which can move from atom to atom easily, whereas non-metals do not, their electrons are 'bound' meaning they cannot move easily. That's why metal are usually good conductors than non-metals.
Poor conductors of electricity consist of
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silver
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aluminum
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distilled water
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copper
Pure water or distilled water doesnot conduct electricity but tap water, rain water or sea water conduct electricity. For electricity to travel through a liquid movement of charge must take place through the liquid. In tap water, rain water or sea water, there are impurities such as salt of $Na,Mg \; and \; Ca$. They behave as the charge carriers for conduction of electricity. But in distilled water there are no impurities i.e. no ions. There are only neutral water molecules. So, distilled water doesnot conduct electricity.
Why is electrical wiring usually made from copper?
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Because copper is shiny.
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Because copper conducts electricity.
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Because copper is not magnetic
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none of these
Copper is usually used for copper wiring because copper conducts electricity. Because electrical conductivity of copper is good enough and it is cheap too. So it is used in wiring.
Which of the following materials is an electrical conductor?
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Silver
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Silver-coloured plastic
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Cork
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Rubber
Which of the following materials is an electrical insulator?
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Aluminium
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Gold
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Rubber
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all of these