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( 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?
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Conductors and insulators
• Take a close look at this wire.•
There is metal on the inside and plastic onthe outside.• Why?
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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.
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Conductors and insulators• Examples of metals that are conductors of
electricity:o aluminium
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Conductors and insulators• Examples of metals that are conductors of
electricity:o iron
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Conductors and insulators• Examples of metals that are conductors of
electricity:o copper
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Conductors and insulators• Examples of metals that are conductors of
electricity:o gold
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Conductors and insulators• Examples of metals that are conductors of
electricity:o silver
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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
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Conductors and insulators
• 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 .
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Conductors and insulators
• Examples of non-conductors ofelectricity:
o paper
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Conductors and insulators
• Examples of non-conductors ofelectricity:
o rubber
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Conductors and insulators
• Examples of non-conductors ofelectricity:
o wood
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Conductors and insulators
• Examples of non-conductors ofelectricity:
o glass
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Conductors and insulators
• Examples of non-conductors ofelectricity:
o clay
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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?
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Using electricity safely• Never try to repair any
electrical equipment orelectrical socket yourself.
• Get an adult or anelectrician who knowshow to repair it.
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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.
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Using electricity safely• Ensure that there are no
exposed wires inelectrical equipment.
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Using electricity safely
• Never touchswitches or
electrical equipmentwith wet hands.
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Using electricity safely
• Do not put toomany plugs into
one socket.
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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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