Page 144 - Science Class 08

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Electrical Charge and Flow of Electricity

• Electric Charges • Electric Charges in Atoms
• Charging a Body • Electroscope
• Electric Current • Lightning

Electricity is a flow of ny par cles called
electrons which can travel through wires. This
flow is o en called an electric current. Just like Aim : To show that materials get electrified
water which can only flow down a hill, an on rubbing.
electric current can only flow if there’s Method:
something to give it a ‘push’. Take out the ruler from your instrument box.
The word “electricity” comes from the Greek Rub rigorously in your hair. Remember that,
word electron, which means “amber”. In about the ruler and your hair should be dry. A er
600 BC, a Greek philosopher Thales no ced rubbing, bring the rubbed part of the ruler
that a strange thing happened when he rubbed near the small pieces of paper. What do you
a piece of amber with a woollen cloth. As a observe?
result of fric on, the amber acquired the
property of a rac ng to itself light weight
objects like pieces of straws and paper. Now,
we can say that the amber has got electrified.
Thales no ced this unique property of ma er
but he could not define this property.

Nowadays, we are familiar with the electricity
generated by rubbing two different substances,
The electric charges produced are called sta c
electricity. The word sta c means sta onary or
You will no ce that the ruler is a rac ng the
at rest. The electricity that travels along wire is
electricity in mo on. It is called current pieces of paper. It is because, the ruler has
electricity. got electrified due to rubbing.

144 Science-8