Electricity on the Move

1
Electricity on the Move
2
Current Electricity

• Unlike static electricity, which does not move
  except when discharged, current electricity is a
  continuous flow of electric charge.
• An example of this is a battery. When we hook
  something up to a battery, the electrical current
  flows through a path called a circuit.

3

• Current Electricity
• http//www.brainpop.com/science/energy/currentelec
  tricity/preview.weml

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Lighting a Light Bulb

• In order for a light bulb to light there must be
  a closed path to connect all of its components.
• This closed path is called a circuit.

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Circuit Measurements

• Electric Current - Flow of electrons through a
  material.
• Measured as the amount of current that passes a
  conducting wire every second.
• Electrical Potential
• Stored electric energy

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Circuit Measurements

• When given the opportunity, objects will move
  from higher potential energy to an area of lower
  potential energy
• Electrical potential is related to their
  electrical fields and not to height as
  electrons build up on one side they want to
  flow to an area w/ less potential

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Circuits

• A path that allows an electric current to flow
• We can use a circuit diagram to show the path of
  the electric current.
• Copy symbols on page 353 and place by each name
  on the next two slides

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Understanding the Symbols

• Conducting wire allows electricity to flow easily
  
• The cell is an energy source.
• A battery is a combination of cells.
• A lamp is a source of light

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Understanding Symbols (cont)

• A switch will allow you to turn the electricity
  on or off without moving any components of the
  circuit.
• A resistor is used to represent any one of the
  many components (loads) that convert electrical
  energy to other forms of energy. This resists the
  movement of charge through a circuit

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Moving Charges

• The symbol for current is I and the symbol for
  charge is Q, t is used to represent time.
• Current charge moving past a point
• time
• I Q
• t

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• Charge (Q) is measured in Coulombs (C)
• Current (I) is measured in Amperes (A)
• Time (t) is measured in seconds (s)

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Answer the following Questions

1. How is static and current electricity different?
2. Give a real life example of one way that you have
   used static electricity and current electricity?
3. What is it called when current electricity flows
   through a path?
4. If 320 C of charge pass a point in a conductor in
   7 min, what is the current through the point in
   the conductor? (Dont forget the units!)

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Voltage

• Voltage causes current to flow through an
  electrical circuit
• Volt unit of measure to measure this potential
• A Voltage Source (battery or generator) is
  required to maintain the electrical potential in
  a circuit.

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Electrical Current

• Water flowing thru a pipe depends on more than
  the angle of the pipe. It also depends on the
  length of the pipe, diameter of the pipe and if
  the pipe is clogged or open.
• Electrical Current is measured in Amperes
• Amount of Electrical Current ( amps) depends on
  more than just Voltage, it depends on the
  Resistance found in the circuit.

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Electrical Resistance

• the opposition to the flow of electricity
• measured in Ohms symbol is the Greek letter
  Omega -
• Water flowing thru a pipe depends on more than
  the angle of the pipe. It also depends on the
  length of the pipe, diameter of the pipe and if
  the pipe is clogged or open.
• Electricity will take the path of least
  resistance
• The greater the resistance, the less current
  there is for a given voltage.
• a. Longer wires have greater resistance than
  short wires
• b. Thin wires have more resistance than thick
  wire
• c. High conductors have less resistance than
  insulators