Electrical Circuits - 8th Grade Unit#2

Indicators and Objectives for this Unit

5. 6. C. Electricity and Magnetism
2. Cite evidence supporting that electrical energy can be produced from a variety of energy sources and can itself be
transformed into almost any other form of energy.
a. identify various energy sources and the energy transforming devices used to produce electrical energy
* Wind (generators, wind mills)
* Sun (solar cells)
* Water (turbines)
* Fossil fuels (engines)
b. Cite examples that demonstrate the transformation of electrical energy into other forms of energy.
c. Investigate and describe that some materials allow the quick, convenient, and safe transfer of electricity
(conductors), while others prevent the transfer of electricity (insulators).
d. Identify and describe the energy transformations in simple electric circuits.
3. Identify and describe magnetic fields and their relationship to electric current.
a. Investigate and describe the magnetic fields surrounding various types of magnets using materials, such as iron filings and small compasses.
* A single bar magnet
* Two bar magnets with like poles facing
* Two bar magnets with opposite poles facing
* A horseshoe magnet
b. Explain ways to change the strength of a simple electromagnet by varying the number of coils wrapped, the amount of electricity in the wire, the number of batteries used, and whether or not an iron core is used.
c. Describe how the electromagnet demonstrates the relationship of magnetism and electricity and identify common devices that demonstrate application of this relationship.
* Electric motors (fans, hair dryers, can openers)
* Electrical generators (turbine)
d. Describe that electricity moving through a wire produces a magnetic force on materials placed near the wire.
* Iron filings
* Compasses

1st Big Assignment+ Please look up these

Vocabulary Words to look up and put in your journal

Electricity
Electric current
Atom
Electron
Proton
Neutron
Charge
Voltage
Electric circuit
Insulator
Conductor
Magnet
Electromagnet
Alternative current
Direct current
Electromagnetic induction

Please read this article and complete the work below in your journal

What Is Electricity?
By Brandi Waters

¹ Electricity is a big part of our lives. It powers our lights. It can heat and cool our homes. It can make our televisions and computers work. It can even power our cars! We all use electricity every day, but what is it?
² First, you have to know about atoms. All matter is made of atoms. Atoms are very small. They are so small that you cannot see them without a special microscope. Atoms are made up of protons, neutrons, and electrons. Protons and electrons both have an electrical charge. Protons have a positive charge. Electrons have a negative charge. Neutrons do not have a positive or a negative charge. Most atoms have the same number of protons and electrons. Protons and neutrons form the nucleus of the atom. The nucleus is at the center of an atom. Electrons circle around the nucleus like the planets orbit the sun.

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³ Scientists have learned that electrons can move from one atom to another. This creates electricity. You can see electricity in many forms. Lightning is a form of electricity. When you pull a sweater over your hair or rub your feet on the carpet you create static electricity. Electricity can also be made by man. This is how we get electricity to use at our houses. There are many ways that it can be made. It can be made using energy from water flowing down at a dam. It can be made by using the power of the wind. It can also be made by burning fuel. After electricity has been made, it can be moved to other places. A wire is a way of moving electricity. Electrons move from atom to atom along the wire. This creates a current of electricity. Wires run from electrical power plants to homes, schools, and businesses. The wires carry electricity to power our lights and many of our electronic devices.
Copyright © 2011 edHelper

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Assignment=Explain in your journal what you think a GOOD title for the last paragraph of the reading could be and why?

Please copy this assignment in your journal and complete it there

What Is Electricity?

1.	You have to know about ______ to understand what electricity is. Lightning Money Atoms Wires

2.	______ have a negative electrical charge. Protons Electrons Neutrons All of the above

3.	Electricity can be made by ______. Falling water Burning fuel Wind All of the above

4.	Electricity is created when______.

5.	How is electricity brought to our homes?

What Is Electricity?In your journal, Please Draw a picture of an atom with six protons, six neutrons, and six electrons. You have just drawn a picture of a carbon atom! Label a proton, a neutron, an electron, and the nucleus of the atom.

What Is Electricity?In your journal, List as many reasons as you can think of using coal is a bad way of making electricity. Most of the electricity made in the United States comes from burning fuels, such as coal. Why do you think that people do not like this method of making electricity? List as many reasons as you can think of.

Please copy this "cloze" assignment in your journal and complete it there

What Is Electricity?
By Brandi Waters

schools	both	over	work
another	move	moving	after
matter	charge	moved	electrical
negative	along	fuel	electronic
current

Directions: Fill in each blank with the word that best completes the reading comprehension.

     Electricity is a big part of our lives. It powers our lights. It can heat and cool our homes. It can make our televisions and computers (1)  _______________________  . It can even power our cars! We all use electricity every day, but what is it?
     First, you have to know about atoms. All (2)  _______________________   is made of atoms. Atoms are very small. They are so small that you cannot see them without a special microscope. Atoms are made up of protons, neutrons, and electrons. Protons and electrons (3)  _______________________   have an electrical charge. Protons have a positive charge. Electrons have a (4)  _______________________   (5)  _______________________  . Neutrons do not have a positive or a negative charge. Most atoms have the same number of protons and electrons. Protons and neutrons form the nucleus of the atom. The nucleus is at the center of an atom. Electrons circle around the nucleus like the planets orbit the sun.
     Scientists have learned that electrons can move from one atom to (6)  _______________________  . This creates electricity. You can see electricity in many forms. Lightning is a form of electricity. When you pull a sweater (7)  _______________________   your hair or rub your feet on the carpet you create static electricity. Electricity can also be made by man. This is how we get electricity to use at our houses. There are many ways that it can be made. It can be made using energy from water flowing down at a dam. It can be made by using the power of the wind. It can also be made by burning (8)  _______________________  . (9)  _______________________   electricity has been made, it can be(10)  _______________________   to other places. A wire is a way of (11)  _______________________   electricity. Electrons(12)  _______________________   from atom to atom (13)  _______________________   the wire. This creates a(14)  _______________________   of electricity. Wires run from (15)  _______________________   power plants to homes,(16)  _______________________  , and businesses. The wires carry electricity to power our lights and many of our(17)  _______________________   devices.

Please copy this assignment in your journal and complete it there

What Is Electricity?

1.	You have to know about ______ to understand what electricity is. Wires Lightning Atoms Money

2.	______ have a negative electrical charge. Protons Electrons Neutrons All of the above

3.	Electricity can be made by ______. Falling water Burning fuel Wind All of the above

4.	Electricity is created when______.

Electrical Circuits
By Brandi Waters

¹ You have already learned about electricity. You know that electricity is a stream of electrons moving from atom to atom. Electrons have a negative charge. They move toward atoms with a positive charge. When electrons move, electricity is made.

^{Assignment=Explain in your journal what you think a GOOD title for the last paragraph of the reading could be and why?}

² Electrons cannot jump across a distance. There must be a path for electrons to follow. The path must be a series of atoms that can accept an electron. We call this path a circuit. People have learned how to build and manipulate circuits to move electricity. We use circuits to bring electricity into our homes. We use circuits to move electricity through our computers, telephones, toys, and even our cars.

Please copy this main idea and details graphic organizer in your journal and complete it there

³ Every time you flip a light switch in your house, you are using a circuit. The light bulb glows when electrons are flowing through it. The light bulb only glows when the switch is on. This is because the circuit is complete when the switch is on. Wiring in your house forms a path for electricity to flow. The wires are attached to the light bulb. The wires are also connected to the switch on the wall. When the switch is turned off, there is a break in the circuit. When the circuit is broken, electricity cannot flow through the light bulb. When the switch is turned on, the switch forms a bridge that completes the circuit. Electrons can flow through the wires, through the switch, and through the light bulb. The light bulb glows and lights your room. Circuits help people control when and where electricity flows.
Copyright © 2011 edHelper

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Assignment=Explain in your journal what you think a GOOD title for the last paragraph of the reading could be and why?

Electrical CircuitsPlease copy this assignment in your journal and complete it there

1.	Electricity is ______. Negatively charged A stream of electrons Made when electrons move from atom to atom All of the above

2.	Electrons flow on a path called ______.

3.	People use electrical circuits to ______. Control where electricity flows and when it is flowing Control how much electricity is made Make electrons jump to positively charged atoms All of the above

4.	When a switch in an electrical circuit is turned off, ______.

5.	What is used to make the circuits, or paths that electricity can flow through, in our homes? Electrons Switches Light bulbs Wires

Please click this site below , hit enter, complete the electrical circuit reading and activity.

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NOW take 15 or more notes about what you learned from the reading and activity.

Electrical CircuitsASSIGNMENT=In your journal,explain what a switch does in an electrical circuit. How does the circuit change when the switch is turned from on to off?

Electricity

magnetic field parallel circuit electric field

electromagnet fuse conductor

direct current voltage alternating current

insulator electricity kilowatt-hour

circuit lodestone ground

generator short circuit series circuit

resistor compass ampere

charge magnet static electricity

lightning rod

Matching

Assignment-In your journal. Match each definition with a word above

1. An electric current flowing only in one direction.

2. The amount of energy used when you consume one kilo-watt of power in one

hour.

3. A piece of metal that stands at the highest point of a building and is connected to

the Earth. The purpose of the piece of metal is to ground the large amount of

electrical energy in the event of a lightning strike.

4. A machine that produces electricity by changing energy of motion into electrical

energy.

5. An electrical connection that allows electrons to be carried away in the event of a

problem.

6. A unit used to measure current.

7. A magnet created when electric current flows through a coil of wire.

8. Energy formed by the motion of protons and electrons.

9. A measure of the amount of electricity in an atom that is determined by the extra

positive or negative particles that an atom has.

10. The area around charged particles where electric forces occur.

Electrical CircuitsASSIGNMENT=We know that batteries make electricity for our flashlights and other devices. If you look closely at a battery, you will see that one end has a + on it and the other end has a - on it. Use what you have learned to draw a picture of how you would build a simple electrical circuit using a battery, wire, and a light bulb. Label the + and - ends on the battery and use arrows to show which way the electrons will flow. Remember, the circuit must be complete. Your circuit should follow a circular path.

Please copy this assignment in your journal and complete it there

Electrical Circuits
By Brandi Waters

bulb	negative	broken	build
move	moving	bring	positive
wall	series	across	electricity
people	accept	only	break
switch

Directions: Fill in each blank with the word that best completes the reading comprehension.

     You have already learned about electricity. You know that electricity is a stream of electrons(1)  _______________________   from atom to atom. Electrons have a (2)  _______________________   charge. They move toward atoms with a (3)  _______________________   charge. When electrons move, electricity is made.
     Electrons cannot jump (4)  _______________________   a distance. There must be a path for electrons to follow. The path must be a (5)  _______________________   of atoms that can (6)  _______________________   an electron. We call this path a circuit. (7)  _______________________   have learned how to (8)  _______________________   and manipulate circuits to move electricity. We use circuits to (9)  _______________________   electricity into our homes. We use circuits to(10)  _______________________   electricity through our computers, telephones, toys, and even our cars.
     Every time you flip a light switch in your house, you are using a circuit. The light bulb glows when electrons are flowing through it. The light bulb (11)  _______________________   glows when the switch is on. This is because the circuit is complete when the switch is on. Wiring in your house forms a path for (12)  _______________________   to flow. The wires are attached to the light bulb. The wires are also connected to the switch on the (13)  _______________________  . When the switch is turned off, there is a (14)  _______________________   in the circuit. When the circuit is (15)  _______________________  , electricity cannot flow through the light bulb. When the switch is turned on, the switch forms a bridge that completes the circuit. Electrons can flow through the wires, through the (16)  _______________________  , and through the light (17)  _______________________  . The light bulb glows and lights your room. Circuits help people control when and where electricity flows.

Multiple Choice

Please copy in your journal and Select the definition that most nearly defines the given word.

11. charge

A. A measure of the amount of electricity in an atom that is determined by the extra

positive or negative particles that an atom has.

B. A hard, black, naturally magnetic rock.

12. series circuit

A. A magnet created when electric current flows through a coil of wire.

B. An electric circuit that has only one path for the current.

13. circuit

A. The area around charged particles where electric forces occur.

B. A closed path along which electricity flows.

14. magnet

A. An object with two poles that attracts iron and steel.

B. The force that pushes electricity or a current. In most homes this force is 110 volts.

15. lodestone

A. A path that allows most of the current in an electric circuit to flow around or away

from the principal elements or devices in the circuit.

B. A hard, black, naturally magnetic rock.

16. direct current

A. The amount of energy used when you consume one kilo-watt of power in one hour.

B. An electric current flowing only in one direction.

17. alternating current

A. An electric current that reverses its direction of flow at regular intervals.

B. A unit used to measure current.

18. voltage

A. An electrical connection that allows electrons to be carried away in the event of a

problem.

B. The force that pushes electricity or a current. In most homes this force is 110 volts.

19. magnetic field

A. The space around a magnet where the force of the magnet can be felt.

B. This has a magnetized needle that is attracted to the earth's north magnetic pole.

20. static electricity

A. An electric circuit that has only one path for the current.

B. A charge that stays on an object instead of flowing in a current.

Please copy this assignment in your journal and complete it there

Electrical Circuits

1.	Electricity is ______. Negatively charged A stream of electrons Made when electrons move from atom to atom All of the above

2.	Electrons flow on a path called ______.

3.	People use electrical circuits to ______. Control where electricity flows and when it is flowing Control how much electricity is made Make electrons jump to positively charged atoms All of the above

4.	When a switch in an electrical circuit is turned off, ______.

PLEASE READ THIS ARTICLE AND ANSWER THE FOLLOWING ASSIGNMENTS IN YOUR JOURNAL

Electric Current
By Cindy Grigg

¹ The electrical wires in your house make a path for the electricity to run through. Electricity is also called electric current. Electric current is a steady flow of electric charges moving from one place to another. Electric currents move in a path called a circuit. If the circuit is complete, or unbroken, then the electric current can be used to do something. For example, when you turn on a light switch in your house, you complete the circuit. Electric current can flow through the wires of the house to the light bulb. The light comes on. Turn the light switch off. The electric circuit is not complete any more. The switch opens a small gap to turn off the light. Electric current can no longer flow through the wires to the light bulb. A switch opens or closes the circuit. Electric current flows like water in a river bed.

Assignment=Explain in your journal what you think a GOOD title for the last paragraph of the reading could be and why?

Please copy this assignment in your journal and complete it there

_____________________________

Date ___________________

Electric Current

1.	Electric current can move in a path called ______. Static A charge Electricity A circuit

2.	What does a switch do to a circuit?

3.	Electricity is ______. When electric charges move in a circuit Another name for electric current Both A and B Neither A nor B

4.	To have a current, electrical charges must be ______. Positive Flowing Static Repelling

Electric Current"Electric current flows like water in a river bed." Explain in your journal why this is a true statement.

Please click this site below , hit enter, click the 2nd of 5 pictures, complete the electrical conductors and insulators reading and activity.

http://www.andythelwell.com/blobz/

NOW take 15 or more notes about what you learned from the reading and activity.

Electric CurrentIn your journal, describe what happens when you turn on a light switch in your house. Draw a picture to illustrate your paragraph.

Please copy this "cloze" assignment in your journal and complete it there

Electric Current
By Cindy Grigg

river	make	circuit	path
turn	when	water	longer
flows	bulb	small	something
light	through	flow	another

Directions: Fill in each blank with the word that best completes the reading comprehension.

The electrical wires in your house (1) _______________________ a path for the electricity to run(2) _______________________ . Electricity is also called electric current. Electric current is a steady(3) _______________________ of electric charges moving from one place to(4) _______________________ . Electric currents move in a (5) _______________________ called acircuit. If the circuit is complete, or unbroken, then the electric current can be used to do(6) _______________________ . For example, (7) _______________________ you turn on a light switch in your house, you complete the circuit. Electric current can flow through the wires of the house to the light(8) _______________________ . The light comes on. Turn the (9) _______________________ switch off. The electric circuit is not complete any more. The switch opens a (10) _______________________ gap to (11) _______________________ off the light. Electric current can no (12) _______________________ flow through the wires to the light bulb. A switch opens or closes the (13) _______________________ . Electric current (14) _______________________ like(15) _______________________ in a (16) _______________________ bed.

Please copy this assignment in your journal and complete it there

Electric Current

1.	Electric current can move in a path called ______. Static A circuit A charge Electricity

2.	What does a switch do to a circuit?

3.	Electricity is ______. When electric charges move in a circuit Another name for electric current Both A and B Neither A nor B

4.	To have a current, electrical charges must be ______. Static Flowing Repelling Positive

Please click this site below , hit enter, click the 3rd of 5 pictures, complete the electrical switches reading and activity.

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Review

21. The magnetic force is strongest at a magnet's poles.

A. True

B. False

22. An electromagnet is a temporary magnet.

A. True

B. False

23. What is the most dangerous part of electricity?

A. The charge

B. Electricity is not dangerous at all.

C. The current

D. The voltage

24. Thomas designs an electric circuit that has 2 batteries connected in series and 1 bulb.

If one of the batteries dies, the brightness of the bulb remains the same.

A. False

B. True

25. What does a switch use to make or break an electric current?

A. Resistors only

B. Conductors and insulators

C. Conductors and resistors

D. Insulators and resistors

26. What did Benjamin Franklin invent in 1752?

A. A kite

B. A key

C. Lightning

D. A lightning rod

27. Lodestone is a natural mineral that possesses magnetic properties.

A. False

B. True

28. What is the area around charged particles where electric forces occur?

A. A power field

B. An electromagnetic field

C. A magnetic field

D. An electric field

29. Emily can control the brightness of her living room lights by turning a knob. If Emily

dims the lights, the knob increases the resistance to the electric current.

A. True

B. False

30. What good insulator material is often used to coat electrical wires?

A. Plastic

B. Paper

C. Copper

D. Aluminum

Please click this site below , hit enter, click the 4th of 5 pictures, complete the changing circuits reading and activity.

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NOW take 15 or more notes about what you learned from the reading and activity.

Electricity - Circuit Construction

http://phet.colorado.edu/en/simulation/circuit-construction-kit-dc-virtual-lab

Electricity - ADV. circuit construction

http://phet.colorado.edu/en/simulation/circuit-construction-kit-ac-virtual-lab

Electricity- Signal Circuit

http://phet.colorado.edu/en/simulation/signal-circuit

Electricity - Adv-Resistance in a Wire

http://phet.colorado.edu/sims/resistance-in-a-wire/resistance-in-a-wire_en.html

Electricity - Ohms Law -Adv

http://phet.colorado.edu/sims/ohms-law/ohms-law_en.html

Electric Generator

http://phet.colorado.edu/en/simulation/generator

Faradays Law

http://phet.colorado.edu/en/simulation/faradays-law

Faradays Electromagnetic Lab

http://phet.colorado.edu/en/simulation/faraday

Electric Circuit

http://phet.colorado.edu/en/simulation/circuit-construction-kit-dc

Electricity -

Battery-Resistor Circuit

http://phet.colorado.edu/en/simulation/battery-resistor-circuit

Battery Voltage

http://phet.colorado.edu/en/simulation/battery-voltage

ELECTROMAGNETISM

Producing and Supplying Electricity: Garden of Amps

¹ Most plants grow in pots or in gardens. However, some plants are made from steel and concrete. These plants, electrical power plants, are very important to the millions of people around the world who depend on electricity each day. The seeds for electricity production were planted during the 1800s. In 1819 a Danish scientist named Hans Christian Oersted discovered by accident that electricity and magnetism were connected. Oersted was demonstrating how electrical currents could produce heat when he noticed a strange sight. There was a compass on a nearby table, and when the wires were connected in his circuit to the power source, the needle on the compass swung around. When he disconnected the wires, the compass needle returned to its normal position pointing towards the magnetic north pole. Electricity had magnetic pull!

Please copy this graphic organizer in your journal and complete it therefrom the paragraph above

Main Idea and Details Graphic Organizer

² In 1820, French scientist André Ampere proved that parallel wires carrying electric currents in the same direction in a circuit would attract each other like unlike poles on the ends of bar magnets. If the current flowed in opposite directions, the wires would repel each other. Ampere used his observations to make a cylindrical (circular) coil of wire that behaved like a magnet. Today we call cylindrical coils of wire solenoids.

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Main Idea and Details Graphic Organizer

Assignment= In your journal, explain what a solenoid is

³ In 1825, William Sturgeon, an English scientist discovered that you could increase the power of an electromagnet (combination of electricity and magnets) by placing a bar of soft iron inside a coil of wire. In 1831, American Joseph Henry made improvements to Sturgeon's electromagnet by insulating or wrapping the wires to help hold in the heat from the electrical current. This helped to increase the power of the electromagnet. During that same year, Henry helped to develop an electromagnet that was capable of lifting over a ton (2000 pounds).

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Main Idea and Details Graphic Organizer

⁴ The one scientist who had the greatest impact on future electricity production was Englishman Michael Faraday. Faraday used two bar magnets wrapped in electrical coils and sprinkled iron filings onto a piece of paper above the two electromagnets. After the iron filings formed around the electromagnets, Faraday stated that the lines of filings on the paper marked the real lines of electromagnetic force. He is the scientist who called the area around a magnet a magnetic field. The idea of fields is a very important concept in science today.

Assignment= In your journal, explain what a "magnetic field" is.

Please copy this graphic organizer in your journal and complete it therefrom the paragraph above

Main Idea and Details Graphic Organizer

⁵ During the 1830s, Faraday experimented with creating electrical currents by using magnets. His experiment included two coils of wires lying next to each other. One coil of wire had an iron bar inside to make it a stronger magnet. When Faraday sent a current through the coil with the iron bar, he had hoped to create an electrical current in the second coil. What he really saw was a small burst of electricity in the second coil and the end of that experiment. He then realized that he needed to move the wire across the magnetic field to produce the current. Faraday tried the experiment again. He moved the iron bar in and out of the coil and moved the loop of wire across the magnetic field. Each time Faraday did this, he caused an electric current to be induced or made in the second coil. Faraday proved that the movement of magnets and wires within a magnetic field produced electricity. Thus, Faraday planted the ultimate seed, the theory of electromagnetic induction. This meant that electricity could be produced, possibly in large quantities. Around this time Joseph Henry also made the same discovery.

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Main Idea and Details Graphic Organizer

⁶ So how does all of the hard work of these scientists help us today? Each scientist's piece of the electromagnetic puzzle helped to form the theory of electromagnetic induction. Oersted, Ampere, Sturgeon, Henry, and Faraday learned from the experiments of the scientists before them, and they used that knowledge to help build the parts of an extraordinary scientific theory. Today the generators in the world's power plants are built using this theory to generate electricity.

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Main Idea and Details Graphic Organizer

⁷ Generators are large machines built with turbines (cylinders) that have magnets which spin between coils of wires. The stronger the magnet, the faster it turns, and the more coils the machine has, the stronger the voltage or power that is created. Generators produce over 99% of our electricity. There are two types of generators. Alternators (AC) send alternating current that switches directions. As the magnets spin in the machine, they pass the wires going up on one side and down on the other side. The result is a current that changes direction. Alternators, which are the simplest form of generator, are found mostly in houses. Dynamos (DC) send direct currents in the same direction. The magnets in these machines only pass the wires in one direction on each side. Household batteries give direct electrical current.

Assignment= In your journal, explain what a "dynamo" is.

Please copy this graphic organizer in your journal and complete it therefrom the paragraph above

Main Idea and Details Graphic Organizer

⁸ Generators can be powered by different types of fuel. Hydroelectric power plants use moving water to turn the turbines (spinning machines) in the generators to spin the magnets around. The Aswan Dam (Egypt, Africa), the Three Gorges Dam (China), Niagara Falls (New York, U.S.A.), the Hoover Dam (Nevada-Arizona Border, U.S.A.) are the world's most famous hydroelectric power plants. Other types of power plants are geoelectric (coal and oil), geothermal (hot water from underground), solar thermal (heat from the sun), and nuclear (energy from atoms). In these power plants, the fuel produces the steam that makes the turbines turn and, therefore, spins the magnets to produce electricity. How does this electricity travel to our homes?
⁹ The answer is through power lines. Once the electricity is produced, it is transferred from the power plant or station through a series of cables or grid. When electricity is sent from the power station, it measures about 25,000 volts or more. As the electricity travels along the power lines, it passes through transformers. Transformers are like boxes that take in the electricity at a certain voltage on one side and increase or decrease the voltage as it passes through the other side. When the electricity leaves the power plant, the transformers increase the voltage (up to 400,000 volts) because less energy will be lost due to the resistance in the cables. As the electricity is transferred to homes and businesses, the voltage is increased or decreased. The voltages for businesses, factories, and homes are usually 110 to 240 volts and can vary in different countries.

Assignment=Please explain in your journal what a "transformer" is concerning electricity.

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Topic= How Does Electricity Travel To Our Homes?

First=

Next=

Last=

¹⁰ There are times, however, when the circuit from the power plant to our homes is broken. Widespread power outages or blackouts can occur when you have blown or exploded transformers or downed power lines. In 1965 a blown transformer caused a blackout in New York City. Hurricanes and tornadoes are notorious for causing power lines to fall down and, therefore, cause electricity to be lost in those areas.
¹¹ Our methods for producing electricity today come from the extraordinary work of scientists in the 1800s. Without their hard work and cultivation, the seeds for electromagnetism would never have been planted.

Copyright © 2011 edHelper

Please copy this assignment in your journal and complete it there

___________________________

Date ___________________

Producing and Supplying Electricity: Garden of Amps

1.	Solenoids are ____________. A network of wires Rectangular coils of wire A set of parallel wires Cylindrical coils of wire

2.	How did Hans Christian Oersted know that magnetism and electricity were connected?

3.	Dynamos are generators that send _________. Alternating current through wires Circular current through wires Direct current through wires None of the above

4.	André Ampere discovered that _______________. Cylindrical or coiled wires are similar to magnets Rectangular wires attract each other Parallel wires far apart are similar to magnets Parallel wires hung from a ceiling repel each other

5.	What is electromagnetic induction?

6.	How does the voltage of electricity change as it travels from the power plant to our homes?

7.	In 1825 William Sturgeon proved that you could increase the power of an electromagnet by ____________ . Placing an iron bar inside a coil of wire Covering the wires with cloth Attaching the wires to an iron bar Placing the wires far apart

8.	Electricity is produced only at hydroelectric power plants. False True

_____________________________

Date ___________________

Producing and Supplying Electricity: Garden of AmpsAssignment= In your journal, use what you have learned about electricity and research to write a "Did You Know" book about electricity. Make sure you include interesting facts about current and static electricity. See if you can find information about strange mysteries like St. Elmo's Fire and Ball Lightning

_____________________________

Date ___________________

Producing and Supplying Electricity: Garden of Amps
Assignment= In your journal, please write a report about how electricity is produced around the world. Explain why certain areas of the world use certain types of power plants to make electricity.

Please copy this "cloze"assignment in your journal and complete it there

Producing and Supplying Electricity: Garden of Amps

voltage	possibly	wrapping	voltages
theory	thermal	circular	compass
magnetism	thus	fuel	wrapped
blackouts	production	downed	cultivation
blackout	nuclear

Directions: Fill in each blank with the word that best completes the reading comprehension.

     Most plants grow in pots or in gardens. However, some plants are made from steel and concrete. These plants, electrical power plants, are very important to the millions of people around the world who depend on electricity each day. The seeds for electricity production were planted during the 1800s. In 1819 a Danish scientist named Hans Christian Oersted discovered by accident that electricity and(1)  _______________________   were connected. Oersted was demonstrating how electrical currents could produce heat when he noticed a strange sight. There was a compass on a nearby table, and when the wires were connected in his circuit to the power source, the needle on the compass swung around. When he disconnected the wires, the (2)  _______________________   needle returned to its normal position pointing towards the magnetic north pole. Electricity had magnetic pull!
     In 1820, French scientist André Ampere proved that parallel wires carrying electric currents in the same direction in a circuit would attract each other like unlike poles on the ends of bar magnets. If the current flowed in opposite directions, the wires would repel each other. Ampere used his observations to make a cylindrical ((3)  _______________________  ) coil of wire that behaved like a magnet. Today we call cylindrical coils of wire solenoids.
     In 1825, William Sturgeon, an English scientist discovered that you could increase the power of an electromagnet (combination of electricity and magnets) by placing a bar of soft iron inside a coil of wire. In 1831, American Joseph Henry made improvements to Sturgeon's electromagnet by insulating or (4)  _______________________   the wires to help hold in the heat from the electrical current. This helped to increase the power of the electromagnet. During that same year, Henry helped to develop an electromagnet that was capable of lifting over a ton (2000 pounds).
     The one scientist who had the greatest impact on future electricity (5)  _______________________   was Englishman Michael Faraday. Faraday used two bar magnets (6)  _______________________   in electrical coils and sprinkled iron filings onto a piece of paper above the two electromagnets. After the iron filings formed around the electromagnets, Faraday stated that the lines of filings on the paper marked the real lines of electromagnetic force. He is the scientist who called the area around a magnet a magnetic field. The idea of fields is a very important concept in science today.
     During the 1830s, Faraday experimented with creating electrical currents by using magnets. His experiment included two coils of wires lying next to each other. One coil of wire had an iron bar inside to make it a stronger magnet. When Faraday sent a current through the coil with the iron bar, he had hoped to create an electrical current in the second coil. What he really saw was a small burst of electricity in the second coil and the end of that experiment. He then realized that he needed to move the wire across the magnetic field to produce the current. Faraday tried the experiment again. He moved the iron bar in and out of the coil and moved the loop of wire across the magnetic field. Each time Faraday did this, he caused an electric current to be induced or made in the second coil. Faraday proved that the movement of magnets and wires within a magnetic field produced electricity. (7)  _______________________  , Faraday planted the ultimate seed, the theory of electromagnetic induction. This meant that electricity could be produced, (8)  _______________________   in large quantities. Around this time Joseph Henry also made the same discovery.
     So how does all of the hard work of these scientists help us today? Each scientist's piece of the electromagnetic puzzle helped to form the (9)  _______________________   of electromagnetic induction. Oersted, Ampere, Sturgeon, Henry, and Faraday learned from the experiments of the scientists before them, and they used that knowledge to help build the parts of an extraordinary scientific theory. Today the generators in the world's power plants are built using this theory to generate electricity.
     Generators are large machines built with turbines (cylinders) that have magnets which spin between coils of wires. The stronger the magnet, the faster it turns, and the more coils the machine has, the stronger the voltage or power that is created. Generators produce over 99% of our electricity. There are two types of generators. Alternators (AC) send alternating current that switches directions. As the magnets spin in the machine, they pass the wires going up on one side and down on the other side. The result is a current that changes direction. Alternators, which are the simplest form of generator, are found mostly in houses. Dynamos (DC) send direct currents in the same direction. The magnets in these machines only pass the wires in one direction on each side. Household batteries give direct electrical current.
     Generators can be powered by different types of fuel. Hydroelectric power plants use moving water to turn the turbines (spinning machines) in the generators to spin the magnets around. The Aswan Dam (Egypt, Africa), the Three Gorges Dam (China), Niagara Falls (New York, U.S.A.), the Hoover Dam (Nevada-Arizona Border, U.S.A.) are the world's most famous hydroelectric power plants. Other types of power plants are geoelectric (coal and oil), geothermal (hot water from underground), solar (10)  _______________________   (heat from the sun), and (11)  _______________________   (energy from atoms). In these power plants, the(12)  _______________________   produces the steam that makes the turbines turn and, therefore, spins the magnets to produce electricity. How does this electricity travel to our homes?
     The answer is through power lines. Once the electricity is produced, it is transferred from the power plant or station through a series of cables or grid. When electricity is sent from the power station, it measures about 25,000 volts or more. As the electricity travels along the power lines, it passes through transformers. Transformers are like boxes that take in the electricity at a certain voltage on one side and increase or decrease the(13)  _______________________   as it passes through the other side. When the electricity leaves the power plant, the transformers increase the voltage (up to 400,000 volts) because less energy will be lost due to the resistance in the cables. As the electricity is transferred to homes and businesses, the voltage is increased or decreased. The (14)  _______________________   for businesses, factories, and homes are usually 110 to 240 volts and can vary in different countries.
     There are times, however, when the circuit from the power plant to our homes is broken. Widespread power outages or (15)  _______________________   can occur when you have blown or exploded transformers or(16)  _______________________   power lines. In 1965 a blown transformer caused a (17)  _______________________   in New York City. Hurricanes and tornadoes are notorious for causing power lines to fall down and, therefore, cause electricity to be lost in those areas.
     Our methods for producing electricity today come from the extraordinary work of scientists in the 1800s. Without their hard work and (18)  _______________________  , the seeds for electromagnetism would never have been planted.

Please copy this assignment in your journal and complete it there

_____________________________

Date ___________________

Producing and Supplying Electricity: Garden of Amps

1.	Solenoids are ____________. A network of wires A set of parallel wires Cylindrical coils of wire Rectangular coils of wire

2.	How did Hans Christian Oersted know that magnetism and electricity were connected?

3.	Dynamos are generators that send _________. Alternating current through wires Circular current through wires Direct current through wires None of the above

4.	André Ampere discovered that _______________. Parallel wires far apart are similar to magnets Cylindrical or coiled wires are similar to magnets Rectangular wires attract each other Parallel wires hung from a ceiling repel each other

5.	What is electromagnetic induction?

6.	How does the voltage of electricity change as it travels from the power plant to our homes?

7.	In 1825 William Sturgeon proved that you could increase the power of an electromagnet by ____________ . Attaching the wires to an iron bar Covering the wires with cloth Placing the wires far apart Placing an iron bar inside a coil of wire

8.	Electricity is produced only at hydroelectric power plants. False True

POST TEST

· What is electricity?

· What is the difference between static electricity and current electricity?

· What is an atom?

· How does electricity move through a circuit?

· What is the difference between an insulator and a conductor?

· What is the difference between an open circuit and a closed circuit?

· What is static electricity?

· What is magnetism?

· How is earth like a magnet?

· How are electricity and magnetism related?

· What is an electromagnet?

· What are electric motors?

· How does an electric motor work?

· What’s the difference between alternative current and direct current?

Does the number of coils affect magnetic force?

Bradford Science Center

Sunday, August 7, 2011

8th Grade Unit#2 -Electricity

Battery-Resistor Circuit

Battery Voltage

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