# Static%20Electricity - PowerPoint PPT Presentation

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## Static%20Electricity

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### Static Electricity Electrical Charge: Is a concentration of electricity – PowerPoint PPT presentation

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Title: Static%20Electricity

1
Static Electricity
• Electrical Charge
• Is a concentration of electricity

2
Unlike Charges
• Attract one another

3
Like Charges
• Repel one another

4
Electric Fields
• The effect an electric charge has on other
charges in the space around it.

5
Strength of Electric Field
• Amount of charge that produces the field
• And the distance from the charge

6
Static Electricity and Charging
• Static electricity is the study of the behavior
of electric charges, including how charge is
transferred between objects.

7
Charges can be Transferred
• Friction
• Contact
• Induction

8
Charging by Friction
• Transferring of electrons

9
Charging by Contact
• Charging by contact occurs when someone actually
touches another object and the electrons are then
transferred (Van de Graaf Generator)

10
Charging By Induction
• A transfer of charge without contact between
materials.

11
Static Discharge
• Occurs when a pathway through which charges can
move forms suddenly. An example would by
lightning.

12
Electric Current Ohms Law
13
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.

14
Two Types of Current
• Direct Current (DC)
• Alternating Current (AC)

15
Direct Current
• Charge flows in one direction
• An example would be a flashlight or most battery
powered devices.

16
Alternating Current
• Is a flow of electric charge that regularly
reverses its direction.
• Electric current in your home and schools are
like this.

17
Conductors and Insulators
• Electrical Conductor
• Electrical Insulator

18
Electrical Conductor
• Is a material through which charge can flow
easily
• For example copper silver and most metals

19
Electrical Insulator
• A material through which a charge cannot flow
through easily.
• For example Wood Plastic rubber and air

20
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.

21
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.

22
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.

23
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.

24
Voltage Sources
• Batteries
• Solar Cells
• Generators

25
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.

26
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.

27
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.

28
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.

29
Circuit Diagrams
• Circuit diagrams shows one or more complete paths
in which a charge can flow.

30
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.

31
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.

32
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

33
Power and Energy Calculations
• Electric Power
• P (Watts) I (Amps) x V (volts)

34
Electrical Energy
• E P x t
• This equation is used to find the electrical
energy used by an appliance.

35
Electrical Safety
• Correct wiring, fuses, circuit breakers,
insulation, and grounded plugs help make
electrical energy safe to use.

36
Home Safety
• Fuses prevents current overload in a circuit.
• Circuit Breakers is a switch that opens when
current in a circuit is too high.

37
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.

38
Electronic Devices
• Electronic Signals
• Vacuum Tubes
• Semiconductors
• Solid-State Components
• Communications Technology

39
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.

40
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.

41
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.

42
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.

43
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.

44
Solid-State Components
• Most modern electronic devices are controlled by
solid-state components.
• Diodes
• Transistors
• Integrated Circuits

45
Diode
• Combines n-type conductor and p-type
semiconductor.
• Changes alternating current into direct current.

46
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

47
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.

48
Communications Technology
• Computer programmable device that can store and
process information.
• Communication devices use microchips to make them
more portable, reliable, and affordable.