8.1%20Electric%20Potential%20Energy%20%20%20%20and%20Voltage

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8.1 Electric Potential Energy and Voltage

• Electrochemical cells convert chemical energy
  intoelectrical energy. Connecting cells together
  forms batteries.
• The ends of batteries are terminals -
  connectingto them can allow electrons to flow
  fromthe battery through a device that
  convertselectric energy into different forms.
• Electric Potential Energy
• Electric energy can do work. Electric energy
  thatis stored is potential energy when it is
  moving itis kinetic energy.

See pages 270 - 271
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Electric Potential Difference

• The amount of electric potential energy per
  coulomb ofcharge is called the potential
  difference or voltage. This can be measuredwith
  a voltmeter.
• Extra electrons will move to a locationwhere
  there is less of them
• Producing Voltage
• Electrodes in an electrolyte chemicallyreact to
  produce electrons and relativelydifferent
  charges on each electrode. Thiscreates a
  potential difference.

A
B
C
D
E
F
See pages 272 - 273
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Source of Electricity

• What do sources of electrical energy dothese
  pictures represent?

Take the Section 8.1 Quiz
See page 274
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8.2 Electric Current

• A complete pathway that allows electrons to flow
  is calledan electric circuit. Electrons flow
  through devices (loads) in thecircuit that
  convert electricity to other forms of energy.
• Basic Circuit Components
• Source source of energy
• Conductor wire where current flows
• Load turns electricity into other forms
• Switch turns circuit on or off

A
E
B
F
C
D
G
See pages 280 - 282
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Current Flow

• The continuous flow of charge in a complete
  circuit iscalled current electricity.
  Electricity is defined as the amount of charge
  passing a point in a conductor every second.
• Current is measured in amperes (A), and can be
  detected with anammeter.
• Conventional Current
• The flow of electricity is from negative to
  positive (the flow of electrons). In the early
  days of electricity research, scientistsmistakenl
  y believed electricity flowed from positive to
  negative.Descriptions of this flow from positive
  to negative still exist today, and is known as
  conventional current.

Take the Section 8.2 Quiz
See pages 283 - 285
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8.3 Resistance and Ohms Law

• Resistance is the property of any material that
  slows downthe flow of electrons, and converts
  electrical energy into other forms.
• Ohms Law -gt just remember VIR
• The greater the amount of resistance, the lower
  the current
• Resistance Voltage Current
• Unit of resistance is the ohm (O)
• Resistance can be measured in a circuit with an
  ohmmeter
• Switch turns circuit on or off
• Circuit resistors are marked withcoloured bands
  that allow you todetermine the ohm value of
  theresistor.
• The resistance of this resistor is

D
A
C
B
Take the Section 8.3 Quiz
See pages 290 - 297