Currents: Thinking Deeper

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What is static electricity?
Static electricity is the build up of charges on
an object, but they do not flow.
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• Static Charge
• What is a charged object?
• A neutral object can become charged by gaining or
  losing electrons. If an object loses electrons,
  it is left with more protons (positive charge)
  than electrons (negative charge).

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Can you transfer charges? Charges must be
transferred from one object to another through
friction, conduction, or induction.

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Friction

• This is the transfer of electrons from one
  object to another by rubbing.

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Conduction

• This is the transfer of electrons from a charged
  object to another object by direct contact.

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Induction

• This is the movement of electrons to one part of
  an object caused by the electric field of another
  object.

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What gains/loses electrons?

• If an object gives up electrons, another object
  gains those electrons. Electrons are only
  transferred from one location to another.

Rubber (-)
Silk (-)
Wool ()
Fur ()
Amber (-)
Glass ()
Charges are not created nor destroyed.
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Static Discharge
When a negatively charged object and a positively
charged object are brought together, electrons
move until both objects have the same charge.
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Lightning
Lightning is an example of static
discharge. During thunderstorms, air swirls
violently. Water droplets within the clouds
become electrically charged.
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Van de Graff Generator

• A Van de Graff generator produces static
  electricity. Electrons are carried up a rubber
  belt and are transferred to the metal sphere.

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Van de Graff Generator
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Series Circuit
In a series circuit, there is only one path for
the current to take.
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Parallel Circuit
In a parallel circuit, there are several paths
for current to take.
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Advantages/Disadvantages

• Series Circuit
• Advantage
• Easy to design and build
• Disadvantage
• When one device fails they all fail
• Energy must be shared by all devices

Parallel Circuit Advantage When one device fails
the others remain on Disadvantage Hard to design
and build
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We Use Electricity Everyday!
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Electrical Safety
Click on the two links below to play two
different internet Electrical Safety games.

• Electrical Safety in the home (Internet Activity)

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Historical Notes

• Alessandro Volta was an Italian physicist who
  invented the battery in 1800 hence Volt
• Georg Simon Ohm was a German physicist who did
  the experiments that resulted in Ohms Law in
  1827
• Andre Marie Ampere was a French mathematician and
  physicist who made many contributions to our
  understanding of electricity in the 1820s

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How electricity arrives in your home.
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Resources

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