Incandescent Lightbulb. Electricity passes through a tungsten (W) filament, which in turn glows white hot (4500F).

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3 Incandescent Lightbulb Electricity passes through a tungsten (W) filament, which in turn glows white hot (4500F). Very inefficient: 90% of the electrical energy is lost to heat.

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5 I am not discouraged, because every wrong attempt discarded is another step forward. I have not failed. I've just found 10,000 ways that won't work.

6 Many of life's failures are men who did not realize how close they were to success when they gave up. Opportunity is missed by most people because it is dressed in overalls and looks like work.

7 Flourescent Lightbulb Electrical charge is given to the mercury vapors inside a tube and The energized gas glows to give off light. CFL Very efficient does not give off heat

8 Halogen Bulbs Other Bulbs LED Light Emitting Diode Tungsten filament Still very hot Electrons through a semiconductor

9 Electricity: Energy from Moving Electrons A Shocking Experience for All

10 Two Types of Electricity Static Electricity and Current Electricity

11 Current Electricity Energy created by a moving stream of electrons. Current electricity is useful and can operate lights, motors, stereos, etc.

12 Two Types of Current Electricity AC DC Alternating current Direct current

13 Alternating current is electricity that is created by large generators. Copper coils spinning in a magnetic field create current which can be transformed up to travel great distances. The coils spinning in and out of the N and S poles in a magnetic field cause the current to alternate back and forth.

14 Alternating Current (A.C.) - Electrons flow back and forth from the energy source. e- e- e- e- Generators, wall outlets, and power lines all carry or produce A.C. AC travels well but is not portable.

15 Direct Current (D.C.) - Electrons flow in only one direction, from the negative terminal to the positive terminal of a battery. _ e- + e- e- Batteries produce direct current electricity. DC does not travel well but is portable.

16 Dry cell batteries create DC and are commonly called flashlight batteries. They come in many sizes and shapes such as C, D, AA, AAA.

17 Dry cells create electricity through a chemical reaction between the damp paste and zinc can that surrounds the cell. This reaction creates a build up of electrons (-) which makes the flat bottom negatively charged. Electrons from the negative side of the battery repel each other from the negative side of the battery to the more carbon rod(+) at the other end of the battery.

18 The inside of a AA dry cell. You can see the carbon rod (+) on the far right next to the chemical paste. The flat zinc (-) can is to the left of the chemical paste.

19 Potential Difference The difference between (-) and (+) in a battery. This difference creates pressure called voltage. The greater the difference between and +, the greater the voltage _ v AA 1.5 v D 6.0 v Lantern 9.0 v Transistor The potential difference can be seen as a slope. The greater the difference the + steeper the + slope. +

20 Electron build up on a D cell vs 9 volt battery. Greater electron build-up = Greater potential difference Greater potential difference = Greater voltage D cell battery 1.5 volts 9 volt battery

21 Inside of a 9 volt = volt cells Inside a lantern battery = volt cells The chemistry inside most dry cells is the same. This chemistry limits the dry cell to 1.5 volts worth of potential difference. Dry cells are wired together inside of 6v and 9v batteries to achieve greater overall voltage.

22 Rechargeable Batteries A different kind ofchemistry allows for many different kinds of batteries in today s world. Nickel Cadmium (NiCd) NiMH (Nickel Metal Hydride) Lithium Ion (Li ion) Reverse the chemical reaction in a battery to create rechargeable batteries that can be used over and over. May get between charges

23 Wet Cell Battery - Two different metals placed into an acid create direct current electricity through chemical reaction. Electrons move from - to +. Zn Cu galvanometer

24 Car Battery (Wet Cell) Electrons will build up on the more reactive negative electrode. These electrons will repel each other from negative to the positive electrode creating a direct current.

25 Conductors - Conductors are materials that allow electrons to pass through them easily. They loosely hold their electrons. Cu Al Copper, Aluminum, most metals, and water are all good conductors of electricity.

26 Insulators (non-conductors) Materials that resist the movement of electrons through them. They hold their electrons tightly. Plastic insulators Glass, plastic, rubber, ceramic, and air are all insulators.

27 Semiconductors materials that conduct better than insulators but not as good as conductors. They will conduct under certain situations. Silicon and Germanium Computer chips LED lights

28 Superconductors Conduct electricity with no resistance at all. Super cold temperatures are required. Maglev trains MRI Particle Accelerators

29 Term Symbol Definition Unit Voltage (E) - The pressure or push behind Volts electrons flowing through a wire. Current (I) - The flow of electrons. Amps Resistance (R) - Opposition to the flow Ohms of electrons.

30 Simple Circuit Simple Lab Circuit Lab

31 Ohm s Law Voltage (E) = Current (I) x Resistance (R) or I = E / R or R = E / I You need more pressure to push a current through high resistance. You need less pressure to push current through low resistance.

32 Circuit - A closed path for electricity to follow. A circuit includes current, voltage, and resistance.

33 Series circuit - More than one type of resistance lined up along the same path. Once the circuit is opened, nothing on the circuit will receive electricity. Old strings of Christmas lights were wired in a series.

34 Parallel Circuit - A circuit that provides an alternate path for electrons to follow should another path be opened. If one light goes out, the others will stay on. Circuits in your home are wired in parallel.

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36 Electricity is created in power plants

37 Electricity is created by large generators.

38 A magnet is spun inside of copper coils. The magnetic field induces electrical current through the copper windings.

39 Current runs from the plant to a substation to increase the voltage so it can travel your home.

40 Step-up transformer increases the voltage so that electricity can travel a distance through power lines.

41 High voltage transmission lines. 110 kv, 500 kv, 750kV kv = kilovolt (1000 volt)

42 High voltage enters to another substation to step down the voltage to a more manageable level.

43 Step-down transformer decreases voltage to a more useable level.

44 Distribution power lines Less than 33kV

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49 Circuit Breaker Panel with circuit breakers When too much amperage (current) flows through a circuit, the breaker switch flips and opens the circuit.

50 Amps x Volts = Watts Example: Lightbulb 3 amps at 25 volts = 75 Watts Central AC 3 amps at 120 volts = 360 Watts Use one of these appliances for an hour and you get a Watt-Hour A 75 Watt lightbulb left on for one hour = 75 watt-hours

51 The power company charges us for kilowatt-hours, there are 1000 watts in a kilowatt. So, if I leave a 100 watt lightbulb on for 10 hours, I would be charged for 1000 watt-hours or 1kilowatt-hour Cost of electricity is approx. $.10 per kilowatt-hour Avg. use in household was 900 kilowatt-hours a month, So the avg. household paid in electricity costs

52 Electrical Safety The next several slides will show a character displaying improper electrical safety behavior. On your own sheet of paper, write down what you see that is dangerous and how the situation could be remedied.

53 Phantom of the Opera

54 Count Dracula

55 The Werewolf

56 Bride of Frankenstein

57 Hunchback of Notre Dame

58 Mummy

59 Young Frankenstein

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61 Static Electricity A non-moving buildup of charges. It is caused by the transfer of electrons. Static electricity is not very useful.

62 All matter is made up of atoms. Atoms are made up of smaller particles protons, neutrons, and electrons. The electrons around the outside some atoms are easy to move. Electrons that move between materials create electrical charges on those materials.

63 Some materials are better at gaining charges while others are better at losing them. Electrons are gained or lost through friction - rubbing objects together. Remember: Electrons are negatively charged and electrons always do the moving.

64 Objects that lose electrons become more positive. Objects that gain electrons become more negative Balloon + Rabbit Fur Negative charge + Positive charge Rubbing creates friction Charges move from one object to the other

65 As in Magnetism: Like charges will repel Opposite charges will attract attract repel

66 St. Elmo s Fire glowing plasma given off by the discharge of a pointed mast on a ship. Named after the patron saint of sailors, St. Erasmus.

67 Lightning is a large static discharge between the ground and a cloud or between clouds.

68 1. Charges within the cloud separate, positive ice crystals to the top and negatively charged rain drops to the bottom. 2. Positive charges within the ground gather on taller objects, attracted to the charges in the cloud. 3. Charges from the cloud rush down to meet with charges from the ground. Lightning is formed.

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72 Lightning can form: - from cloud to ground - from ground to cloud - from cloud to cloud - within the same cloud

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74 Strange, Mysterious Ball Lightning

75 Lightning Rods protect your home from damage.

76 Roy Sullivan Shenandoah National Park Ranger Human Lightning Rod Hit by lightning a record 7 times 1 in 3000 chance of being struck by lightning in your lifetime.

77 Wind Turbine

78 Solar Power

79 Tidal Energy

80 Biomass

81 Geothermal

82 Hydroelectric

83 Biofuel

84 Nuclear Power

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