May the Force be with You
Student A
TASK ONE
Sit with two other "A" students. What subject do all of these words have in
common? Together with your group, write subjects that are connected to all of
these things in the center of the graph. When you finish, tell the teacher your
guesses.
Radiation
Charge
Energy
Fields
Wave
___________________
Current
Electrons
Induction
Potential
Photons
Today's subject will be: ____________________.
TASK TWO
The following words are important for today's lesson. With your dictionary,
match the words with their meanings in Japanese.
1
2
3
4
5
6
7
8
9
10
11
12
_____ FORCE
_____ ELECTROMAGNETIC
_____ POSITIVE
_____ GENERATE
_____ POTENTIAL
_____ TERMINAL
_____ CHARGE
_____ MAGNET
_____ FIELD
_____ IRON
_____ DIFFERENCE
_____ CONDUCTOR
A 領域, (電気･磁気などの力の)場,界磁
B 可能性がある;潜在的な
C 違い,相違
D コイル,導線.
E ソレノイド,筒形コイル
F 電線
G 電荷、充電
H 磁石
I 力
J 陰電気
K 正電気の
L 電池
13
14
15
16
17
18
19
20
21
22
_____ NEGATIVE
_____ ELECTROMOTIVE
_____ WIRE
_____ BATTERY
_____ DEFLECT
_____ SOLENOID
_____ PRODUCE
_____ INDUCTION
_____ COIL
_____ ELECTRON
M 鉄
N 生み出す
O 電極
P 伝導体
Q 向きに曲がっている
R 電磁石の;電磁気の
S 電動の,動電の,起電の,起電的な.
T 電子
U 〈電気･熱などを〉発生させる
V 誘導
TASK THREE
Vocabulary Bingo Game. Choose twelve (16) words from the list
above. Write them in English on the Bingo Sheet below. Listen to
the teacher give English definitions of the words. Circle the words
that you think match the definition.
Now, place the letter of the matching description from the right column on the blank in front of the
number of the left column.
____ 1. COIL
____ 2. SOLENOID
____ 3. POSITIVE
____ 4. INDUCTION
____ 5. CONDUCTOR
____ 6. TERMINAL
____ 7. GENERATE
____ 8. ELECTRON
____ 9. DEFLECT
____10. IRON
A. A very small piece of matter that is negatively charged
B. The amount of electricity an object carries
C. An area or electrical or magnetic energy
D. A type of electrical energy that carries protons
E. The amount of power within an electrical current
F. In electrical English a terminal is a point where a connection in
an electrical circuit is made
G. A silver metal that is magnetic.
H. An object that attracts iron and steel object, and is also
able to repel them
I. A type of electrical energy that carries electrons
J. To be possible when certain conditions exist
____11. NEGATIVE
____12. DIFFERENCE
____13. FORCE
____14. PRODUCE
____15. MAGNET
____16. WIRE
____17. POTENTIAL
____18. ELECTROMAGNETIC
____19. FIELD
____20. CHARGE
____21. BATTERY
____22. ELECTROMOTIVE
K. Any material that easily allows electricity or heat to travel
through it
L. The way that two things are not the same
M. A device that holds electrical energy
N. A twisted wire that an electrical current can travel through
O. A thin metal thread that can be bent and can carry an electrical
current
P. Wire that is wrapped around a magnet or electromagnet
Q. Another word that means to make or to create
R. To give off electrical energy without anything touching it
S. To cause something to change direction
T. A piece of iron that has been made a magnet by an electric
current
U. Moving electricity that is also called volts
V. A word that means to produce electricity
BONUS TASK
Find the words in the puzzle. Write them in the paragraph below.
The unit for measuring electric potential difference is called the volt. Sometimes the
electric potential difference is called voltage. When there is no ____________________
in electrical potential, an electrical charge will not move between two
____________________s. On the other hand, if there is a large ____________________
difference between two points in a ____________________, positive electric charge will
move from higher to lower potential. A ____________________ charge would move from
a lower to a higher potential.
For example, a simple ____________________ rated at 1.5 volts has an
electric potential at the ____________________ terminal that is 1.5
volts above the negative. Frequently this potential difference is
called the emf, or ____________________ ____________________, of the
battery. When the terminals of a battery are connected with a
____________________, an electric circuit is ____________________d. A
potential difference is created between the terminals, and
____________________s flow in the ____________________ in one
direction, away from the negative terminal toward the positive.
TASK FOUR
Pair Work. Your name is Delbert. You are asking Dr. Jane Jolt (Student B) a
question about electromagnetic induction. Read your part of the dialog to your
partner. Listen to your partner. Speak when he or she is finished. Do not look at
your partner's paper.
Delbert:
Jolt:
Delbert:
Jolt:
Delbert:
Jolt:
Hi there, Dr. Jolt!
Pretty good. Hey, could I ask you something?
I don't understand what electromagnetic induction is. Do
you think you could explain it to me?
Delbert:
Jolt:
Really?
Delbert:
Jolt:
Michael Faraday?
Delbert:
That's interesting! I can see from the picture that if you
move the magnet up, the electrons flow in one direction,
but if you move the magnet down, the electrical current
flows in the other direction. And the magnet doesn't touch
the wire coil!
Jolt:
Delbert:
Jolt:
Wow! Ok. I get it. But why is this important?
Delbert:
I see. Ok, let me double check now. Electromagnetic
induction is when a wire is moved across a magnetic field,
and a small electromotive force is produced in the wire.
Jolt:
Delbert:
Jolt:
Delbert:
Jolt:
Delbert:
So to have electromagnetic induction, we need three
things, a magnetic field, a conductive wire, and movement.
Thanks a lot for your help, Dr. Jolt.
Well, I'd better go now. See you later.
Jolt:
Delbert:
Jolt:
You too. 'Bye.
TASK FIVE
Read the article about Electromagnetic Energy. After you finish reading,
please begin the Communication Task.
In 1820 the Danish scientist Hans Christian Oersted found by accident that the magnetized needle of a
compass would realign if brought near a wire that was carrying an electric current. Apparently, a
magnetic field encircles the current-carrying wire. All magnetism arises from moving electric charge.
If a current flows in a helical coil, called a solenoid, the magnetic field will be directed through the
solenoid and out one end. The field curves around and reenters the other end of the solenoid. This is
similar to the shape of the magnetic field around a bar magnet with a south and north pole of the earth.
If an unmagnetized iron rod is inserted into a solenoid, the magnetic field inside the solenoid forces the
electrons in the iron atoms to align their spins, producing domains that reinforce the magnetic field
strength. This arrangement of solenoid and iron rod is an electromagnet and gives a magnetic field
considerably stronger than that caused by the current in the solenoid alone.
Communication Task
Student "B" will ask you questions about the article you have just read. Look at
the article and tell him or her your answers. Then ask Student "B" the
following questions. Write the answers that he or she gives you.
Questions for Student "B"
1.
What are moving electric charges surrounded by?
2.
If an electric charge moves through a magnetic field, what does it experience?
3.
If a positive charge moves from right to left, what direction is it deflected in a magnetic field?
4.
If a negative charge moves across a magnetic field, what direction will it be deflected?
5.
What was the name of the scientist who discovered electromagnetic induction?
6.
What device is electromagnetic induction used in?
TASK SIX
Listen now to the instructor. The instructor will give a short presentation about
electromagnetic energy. As you listen, number the pictures from 1 to 4.
N
S
Direction of Moving
Wires
Direction of
Electric Current
May the Force be with You
Student B
TASK ONE
Sit with two other "B" students. What subject do all of these words have in
common? Together with your group, write subjects that are connected to all of
these things in the center of the graph. When you finish, tell the teacher your
guesses.
Radiation
Charge
Energy
Fields
Wave
___________________
Current
Electrons
Induction
Potential
Photons
Today's subject will be: ____________________.
TASK TWO
The following words are important for today's lesson. With your dictionary,
match the words with their meanings in Japanese.
1
2
3
4
5
6
7
8
9
10
_____ FORCE
_____ ELECTROMAGNETIC
_____ POSITIVE
_____ GENERATE
_____ POTENTIAL
_____ TERMINAL
_____ CHARGE
_____ MAGNET
_____ FIELD
_____ IRON
A 領域, (電気･磁気などの力の)場,界磁
B 可能性がある;潜在的な
C 違い,相違
D コイル,導線.
E ソレノイド,筒形コイル
F 電線
G 電荷、充電
H 磁石
I 力
J 陰電気
11
12
13
14
15
16
17
18
19
20
21
22
_____ DIFFERENCE
_____ CONDUCTOR
_____ NEGATIVE
_____ ELECTROMOTIVE
_____ WIRE
_____ BATTERY
_____ DEFLECT
_____ SOLENOID
_____ PRODUCE
_____ INDUCTION
_____ COIL
_____ ELECTRON
K 正電気の
L 電池
M 鉄
N 生み出す
O 電極
P 伝導体
Q 向きに曲がっている
R 電磁石の;電磁気の
S 電動の,動電の,起電の,起電的な.
T 電子
U 〈電気･熱などを〉発生させる
V 誘導
TASK THREE
Vocabulary Bingo Game. Choose twelve (16) words from the list
above. Write them in English on the Bingo Sheet below. Listen to
the teacher give English definitions of the words. Circle the words
that you think match the definition.
Now, place the letter of the matching description from the right column on the blank in front of the
number of the left column.
____ 1. COIL
____ 2. SOLENOID
____ 3. POSITIVE
____ 4. INDUCTION
____ 5. CONDUCTOR
____ 6. TERMINAL
____ 7. GENERATE
____ 8. ELECTRON
____ 9. DEFLECT
A. A very small piece of matter that is negatively charged
B. The amount of electricity an object carries
C. An area or electrical or magnetic energy
D. A type of electrical energy that carries protons
E. The amount of power within an electrical current
F. In electrical English a terminal is a point where a connection in
an electrical circuit is made
G. A silver metal that is magnetic.
H. An object that attracts iron and steel object, and is also
able to repel them
I. A type of electrical energy that carries electrons
____10. IRON
____11. NEGATIVE
____12. DIFFERENCE
____13. FORCE
____14. PRODUCE
____15. MAGNET
____16. WIRE
____17. POTENTIAL
____18. ELECTROMAGNETIC
____19. FIELD
____20. CHARGE
____21. BATTERY
____22. ELECTROMOTIVE
J. To be possible when certain conditions exist
K. Any material that easily allows electricity or heat to travel
through it
L. The way that two things are not the same
M. A device that holds electrical energy
N. A twisted wire that an electrical current can travel through
O. A thin metal thread that can be bent and can carry an electrical
current
P. Wire that is wrapped around a magnet or electromagnet
Q. Another word that means to make or to create
R. To give off electrical energy without anything touching it
S. To cause something to change direction
T. A piece of iron that has been made a magnet by an electric
current
U. Moving electricity that is also called volts
V. A word that means to produce electricity
BONUS
TASK
Find
puzzle. Write
paragraph below.
the words in the
them in the
The unit for measuring electric potential difference is called the volt. Sometimes the
electric potential difference is called voltage. When there is no ____________________
in electrical potential, an electrical charge will not move between two
____________________s. On the other hand, if there is a large
____________________ difference between two points in a
____________________, positive electric charge will move from higher
to lower potential. A ____________________ charge would move from a
lower to a higher potential.
For example, a simple ____________________ rated at 1.5 volts has an
electric potential at the ____________________ terminal that is 1.5 volts
above the negative. Frequently this potential difference is called the
emf, or ____________________ ____________________, of the battery.
When the terminals of a battery are connected with a ____________________, an electric
circuit is ____________________d. A potential difference is created between the
terminals, and ____________________s flow in the ____________________ in one direction,
away from the negative terminal toward the positive.
TASK FOUR
Pair Work. Your name is Dr. Jane Jolt. You are telling Delbert (Student A) about electromagnetic
induction. Read your part of the dialog to your partner. Listen to your partner. Speak when he or she
is finished. Do not look at your partner's paper.
Delbert:
Jolt:
Delbert:
Jolt:
Delbert:
Jolt:
Delbert:
Jolt:
Delbert:
Jolt:
Hello Delbert. How are you doing?
Sure, what do you want to know?
Sure thing, Delbert. Electromagnetic induction was an
important in electrical science.
You bet it was. It was first discovered by an Englishman by
the name of Faraday.
Yes, that right. Here, look at this picture. In 1831, he
showed that if you suspend a magnet in a coil of wire,
nothing happens. But if move a magnet through a coil of
wire an electric current would go through the wire.
Delbert:
Jolt:
Delbert:
Jolt:
That's right, Delbert. And this is why we call it
electromagnetic induction. The electrical energy from the
magnet goes into the wire from the moving
electromagnetic field.
Magnetic induction is important because it's the main
process in electrical generators.
Delbert:
Jolt:
Delbert:
Right.
Jolt:
You've got it!
Delbert:
Jolt:
Delbert:
Jolt:
No problem, Delbert.
Ok. Have a nice day.
Delbert:
Jolt:
Take it easy.
TASK FIVE
Read the article about Electromagnetic Energy. After you finish reading,
please begin the Communication Task.
Moving electric charges are surrounded by a magnetic field, and magnetic fields interact with magnets.
Thus it is not surprising that electric charges moving through a magnetic field experience a force.
What is surprising is the direction of the deflecting force. If the positive charge moves from right to
left, it is deflected inward. A negative charge moving across the field will be deflected outward.
Michael Faraday, the English scientist showed in 1831 that moving a magnet through coils of wire
would generate an electric current in the wire. If the magnet was plunged into the coil, current flowed
one way. When the magnet was removed, the direction of the electrical current was reversed. This
phenomenon is called electromagnetic induction, and it is the principle underlying the operation of the
generator. As long as the magnet and the coil move relative to each other, a potential difference is
produced across the coil and current flows in the coil.
Communication Task
Ask Student "A" the questions below. He or she will tell you the answers.
Write the answers. Student "A" will then ask you questions about the article
you have just read. Look through the article and tell him or her the answers.
Questions for Student "A"
7.
What did the Danish scientist Oersted discover in 1820?
8.
What circles wires that carry an electric current?
9.
What does magnetism come from?
10. A helical coil of wire is also called what?
11. The poles of a bar magnet are also similar to what?
12. What happens if an unmagnetized iron rod is put inside a solenoid?
TASK SIX
Listen now to the instructor. The instructor will give a short presentation about
electromagnetic energy. As you listen, number the pictures from 1 to 4.
N
S
Direction of Moving
Wires
Direction of
Electric Current
Lecture
In today's lesson, we have learned many things about electromagnetic
forces. For example, we read earlier that in 1820, the Danish scientist
Hans Christian Oersted found by accident that the magnetized needle
of a compass would realign if brought near a wire that was carrying an
electric current. This discovery means that magnetic fields are all
around the current-carrying wire. Scientists now know that all
magnetism arises from moving electric charge. For example, magnetic
charge move from one end to another. The electromagnetic current
flows from one end to the other of a solenoid, which is a helical coil of
wire. The field curves around and reenters the other end of the
solenoid. Later on, scientists discovered that this is similar to the
shape of the magnetic field around a bar magnet, and the magnetic
field of the earth.
Later on, Michael Faraday found out that when a wire is moved across
a magnetic field, a small e.m.f. is produced in the wire. This effect is
called electromagnetic induction; an e.m.f. is induced by the
electromagnetic field. In a complete circuit, an induced e.m.f. causes
an induced current to flow. There are 3 factors essential for
electromagnetic induction
1. magnetic field;
2. wire, and
3. movement.
This law is often called Faraday's law, and it is important in the function
of generators.
But there was another discovery that was made by a German scientist
by the name of Heinrich F.E. Lenz 1834. He found that when an
electrical current is induced, the current produced will also generate a
magnetic field. This electric current always flows in a direction that is
OPPOSITE of the change in magnetic field that causes it. This is called
Lenz's law, and it is very important in the operation of electric motors.