Download Lesson 11

lesson11.notebook
February 26, 2013
Review:
How does energy get to your home?
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efficiency of appliances
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uses of electricity in the home
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conserving electricity
1.
Apr 23­11:28 AM
arrange the following in the correct order to illustrate how electricity gets to your house
2.
3.
Apr 23­11:29 AM
Production and Transfer of Electricity:
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electricity is produced using electrical generators
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a generator is a device that converts mechanical energy into electrical energy
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there are typically two parts to a generator:
(a) Coil of wire
(b) Magnets
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electricity is generated when the coil of wire is rotated inside a magnet
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there are various commercial methods producing electricity
Apr 23­11:34 AM
Apr 26­2:50 PM
(a) Hydroelectric:
­ uses the energy of falling or flowing water to spin a turbine
(b) Thermal:
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uses heat produced from burning fossil fuels including coal, gas, and diesel to boil water
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the resulting steam is used to spin a turbine
(c) Nuclear Energy:
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uses the heat released from a nuclear reaction to boil water
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resulting steam spins the turbine
* See diagram on page 327
Apr 23­11:45 AM
Apr 26­2:51 PM
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lesson11.notebook
Apr 26­2:51 PM
February 26, 2013
Apr 26­2:53 PM
Electricity Transfer:
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electricity is typically produced at 20,000 volts or less
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before this electricity leaves the generating station transformers are used to "step up" the voltage
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a transformer is a device that can increase or decrease voltage
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increasing voltage reduces current and means there is less resistance in the wires thus it can travel easier over long distances
Apr 23­11:48 AM
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when electricity reaches a town it generally is run through a sub station which includes transformers which "step down" the power to a lower voltage and send it around a town
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before it reaches a house it goes through another transformer which reduces voltage to 120 volts or 240 volts which is used by most household appliances
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devices in your house have their own transformers such as video games
Apr 26­2:54 PM
Apr 26­3:06 PM
Apr 26­3:05 PM
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lesson11.notebook
February 26, 2013
*REMEMBER:
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it is important to supply electrical energy at a relatively constant voltage for consumer safety as well as operation of electric device
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any increase or decrease can damage sensitive equipment
SEE DIAGRAM: Page 328
Apr 26­3:07 PM
Apr 26­2:59 PM
Readings:
Pages 324 ­ 328
Questions:
Page 328: #'s 1,2,3,4,5
Apr 26­3:08 PM
Apr 26­3:02 PM
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