Conductors of Electricity

8/11/2019 Conductors of Electricity

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My Pals are Here! Science © 2008 Marshall Cavendish (Singapore) Private Limited© 2009 Marshall Cavendish International (Singapore) Private Limited



( g p )

Questions to think about…

What are electricalconductors and

insulators? Are good conductors

of electricity alsogood conductors of

heat?

How do we useelectricity safely?

© 2009 Marshall Cavendish International (Singapore) Private Limited



Conductors and insulators

• Take a close look at this wire.•

There is metal on the inside and plastic onthe outside.• Why?




Conductors and insulators• Some materials, like copper, allow an

electric current to flow through them.• Such materials are called conductors of

electricity.• Many other metals also conduct electricity

well.• Hence, wires are usually made of metals.




Conductors and insulators• Examples of metals that are conductors of

electricity:o aluminium





electricity:o iron





electricity:o copper





electricity:o gold





electricity:o silver




Conductors and insulators• To prevent the electric current from flowing

out of a circuit, wires are coated with plastic.• Plastic does not allow an electric current to

flow through it.

plastic





• Other than plastic, many other materialsdo not allow an electric current to flowthrough them.

• These materials are called non-conductors of electricity.

•

Non-conductors of electricity are alsocalled insulators .





• Examples of non-conductors ofelectricity:

o paper






o rubber






o wood






o glass






o clay




Using electricity safely• Electricity is useful but it can harm us if we

do not use it carefully.• Other than getting a nasty shock, we can

cause a fire if we do not use electricitycarefully.

So what can we do toprotect ourselves?




Using electricity safely• Never try to repair any

electrical equipment orelectrical socket yourself.

• Get an adult or anelectrician who knowshow to repair it.




Using electricity safely• When repairing any

electrical equipment, propertools with plastic or wooden

handles should be used.• Such materials are non-

conductors of electricity.• They prevent electricity

from flowing from theequipment to our hands.




Using electricity safely• Ensure that there are no

exposed wires inelectrical equipment.




Using electricity safely

• Never touchswitches or

electrical equipmentwith wet hands.




Using electricity safely

• Do not put toomany plugs into

one socket.




Using electricity safely• Use safety devices such as circuit breakers and

fuses.• Sometimes, fires are accidentally caused when

too much current flows through a circuit.• Circuit breakers and fuses break a circuit whentoo much current flows through them.

circuit breaker fuse




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Conductors of Electricity