Static%20Electricity

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Static Electricity

• Electrical Charge
• Is a concentration of electricity

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Unlike Charges

• Attract one another

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Like Charges

• Repel one another

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Electric Fields

• The effect an electric charge has on other
  charges in the space around it.

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Strength of Electric Field

• Amount of charge that produces the field
• And the distance from the charge

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Static Electricity and Charging

• Static electricity is the study of the behavior
  of electric charges, including how charge is
  transferred between objects.

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Charges can be Transferred

• Friction
• Contact
• Induction

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Charging by Friction

• Transferring of electrons

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Charging by Contact

• Charging by contact occurs when someone actually
  touches another object and the electrons are then
  transferred (Van de Graaf Generator)

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Charging By Induction

• A transfer of charge without contact between
  materials.

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Static Discharge

• Occurs when a pathway through which charges can
  move forms suddenly. An example would by
  lightning.

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Electric Current Ohms Law
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Electric Current

• The rate at which charges flows through the lamp
  or wires.
• Current is how much electric charge flows past
  a pint in a circuit during a given time.
• Current is measured in ampes.

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Two Types of Current

• Direct Current (DC)
• Alternating Current (AC)

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Direct Current

• Charge flows in one direction
• An example would be a flashlight or most battery
  powered devices.

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Alternating Current

• Is a flow of electric charge that regularly
  reverses its direction.
• Electric current in your home and schools are
  like this.

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Conductors and Insulators

• Electrical Conductor
• Electrical Insulator

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Electrical Conductor

• Is a material through which charge can flow
  easily
• For example copper silver and most metals

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Electrical Insulator

• A material through which a charge cannot flow
  through easily.
• For example Wood Plastic rubber and air

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Resistance

• Is the opposition to the flow of charges in a
  material.
• The S.I. unit of resistance is Ohm.
• A materials thickness, length, and temperature
  affect its resistance.

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Superconductor

• Is a material that has almost zero resistance
  when it is cooled to low temperatures.
• The best superconductor so far is cooled to 138 K.

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Voltage

• In order for charge to flow in a conducting wire,
  the wire must be connected in a complete loop
  that includes a source of electrical energy.

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Voltage

• Potential Difference is the difference in
  electrical potential energy between two places in
  an electrical field.
• It is measured in joules per coulomb, or volts,
  it can also be known as voltage.

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Voltage Sources

• Batteries
• Solar Cells
• Generators

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Voltage Sources

• Battery is a device that converts chemical
  energy to electrical energy.
• Have terminals that can connect to wires in a
  circuit.
• One terminal is positive and the other is
  negative.

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Ohms Law

• Founded by German Scientist Georg Ohm.
• First determined how resistance and current
  affect voltage.
• Discovered that voltage is not the same
  everywhere in a circuit.
• Hypothesized that resistance reduces the voltage.

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Ohms Law

• Ohms Law the voltage (V) in a circuit equals
  the product of the current (I) and the resistance
  (R).
• V I x R or I V/R
• Increasing the voltage increases the current.
  Keeping the same voltage and increasing the
  resistance decreases the current.

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Circuit Diagrams

• Electric Circuit A complete path through which
  charge can flow.
• Ex. Wiring in a house
• Circuit diagrams use symbols to represent parts
  of a circuit, including a source of electrical
  energy and devices that are run by the electrical
  energy.

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Circuit Diagrams

• Circuit diagrams shows one or more complete paths
  in which a charge can flow.

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Series Circuits

• Series Circuit charge has only one path through
  which it can flow.
• Ex. Christmas Tree Lights
• If one element stops functioning in a series
  circuit, none of the elements can operate.

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Parallel Circuits

• Parallel Circuit is a electric circuit with two
  or more paths through which charges can flow.
• If one element stops functioning in a parallel
  circuit, the rest of the elements still operate.

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Power Energy Calculations

• Electric Power the rate at which electrical
  energy is converted to another form of energy.
• The unit is Watt or joules per second
• Power is often measured in KiloWatts.
• Electric power can be calculated by multiplying
  voltage by current

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Power and Energy Calculations

• Electric Power
• P (Watts) I (Amps) x V (volts)

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Electrical Energy

• E P x t
• This equation is used to find the electrical
  energy used by an appliance.

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Electrical Safety

• Correct wiring, fuses, circuit breakers,
  insulation, and grounded plugs help make
  electrical energy safe to use.

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Home Safety

• Fuses prevents current overload in a circuit.
• Circuit Breakers is a switch that opens when
  current in a circuit is too high.

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Personal Safety

• Grounding when the electric takes a shorter
  path to a wire which leads to the ground. This
  is a transfer of excess charge through a
  conductor.

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Electronic Devices

• Electronic Signals
• Vacuum Tubes
• Semiconductors
• Solid-State Components
• Communications Technology

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Electronic Signals

• Electronics the science of using electric
  current to process or transmit information.
• Electronic Signal is information sent as
  patterns in the controlled flow of electrons
  through a circuit.

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Electronic Signals

• Electronics conveys information with electrical
  patterns called analog and digital signals.
• Analog Signal is a smoothly varying signal
  produced by continuously changing the voltage or
  current in a circuit.
• Information is encoded in the strength or
  frequency of the analog signal.

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Electronic Signals

• Digital Signal encodes information as a string
  of 1s and 0s.
• Digital Signal is like Morse Code, when the
  current is off it produces a 0 and when it is on
  it produces a 1.
• Digital is more reliable than analog.

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Vacuum Tube

• Controls the flow of electrons in early
  electronic devices.
• Vacuum tubes can change alternating current into
  direct current, increase the strength of a
  signal, or turn a current on or off.
• Example TV tubes
• Problem burn out frequently and need replaced.
  They are also too large for small devices.

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Semiconductors

• Semiconductor is a crystalline solid that
  conducts current only under certain conditions.
• Made with silicon or germanium
• Two types of conductors
• N-type current flows as electrons
• P-type current flows as positive charge.
• When the two conductors are joined electrons from
  the n-type are attracted to the positive p-type
  conductor.

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Solid-State Components

• Most modern electronic devices are controlled by
  solid-state components.
• Diodes
• Transistors
• Integrated Circuits

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Diode

• Combines n-type conductor and p-type
  semiconductor.
• Changes alternating current into direct current.

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Transistors

• Has three layers of semiconductors. Current
  flowing through its center layer changes its
  resistance.
• Can be used a switch, because the small current
  can turn another current on or off.
• Can be used as an amplifier

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Integrated Circuits

• A thin slice of silicon that contains many
  solid-state components.
• Commonly known as chips or microchips
• Used in pages, mobile phones, and computers.

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Communications Technology

• Computer programmable device that can store and
  process information.
• Communication devices use microchips to make them
  more portable, reliable, and affordable.