Download 15 Electricity and Magnetism

Supplemental
Worksheets
Name
Date
Class
Quick Vocabulary
Lesson 1
Lesson 2
electric conductor material in which
charge definite quantity of
electric charges easily move
electric discharge loss of an
electric circuit closed, or complete,
unbalanced electric charge
path in which an electric current
flows
electric field invisible region around
a charged object where an electric
force is applied
electric force a force that two
electrically charged objects apply
to each other
electric insulator material in which
electric charges cannot easily move
electrically charged having an
unbalanced amount of positive
charge or negative charge
electrically neutral having equal
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
electricity
amounts of positive charge and
negative charge
electric current movement of
electrically charged particles
electric resistance measure of how
difficult it is for an electric current
to flow in a material
generator machine that transforms
mechanical energy to electric
energy
light electromagnetic radiation you
can see
voltage amount of energy used to
move one coulomb of electrons
through the circuit
nucleus basic or essential part; core
Electricity and Magnetism
3
Name
Date
Class
Quick Vocabulary
Lesson 3
electromagnet temporary magnet
made with a current-carrying wire
coil wrapped around a magnetic
core
magnet an object that attracts iron
and other materials that have
magnetic qualities similar to iron
magnetic domain region in a
magnetic material in which the
magnetic fields of the atoms all
point in the same direction
magnetic force push or pull a
magnetic field applies to either a
magnetic material or an electric
current
magnetic material material that is
attracted to a magnet
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
4
Electricity and Magnetism
Name
Date
Class
Lesson Outline
LESSON 1
Electric Charges and Electric Forces
A. Electric Charges
1. Each atom contains a core called the
.
a. The nucleus is made up of smaller particles called protons
and
.
b. Atoms also contain
, which move around the nucleus.
c. Protons and
have electric charge.
2. Electric charges are either positive or
.
a. Protons have
charge; electrons have
charge.
b. Atoms are
because they have equal amounts of
positive and negative charges.
c. Electrically neutral objects become
when they gain or
lose electrons.
d. An object that loses electrons becomes
charged.
e. An object that gains electrons becomes
charged.
is the loss of unbalanced electric charge by an object.
a. Some electric discharge occurs
, for example, maybe
you have noticed that static cling lasts longer on dry days.
b. A lightning strike is an example of an electric discharge that
occurs
4.
.
move at different rates through different materials.
a. Materials through which electric charge moves easily are
called
.
b. Materials through which electric charge cannot move easily are
called
10
.
c. Examples of insulators include plastic, wood, and
.
d. Some of the best conductors of electric charge are
.
Electricity and Magnetism
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
3.
Name
Date
Class
Lesson Outline continued
B. Electric Fields and Electric Forces
1. An electric charge is surrounded by a(n)
.
a. Charged objects do not have to
to exert a force on
each other.
b. Scientists know that there is a(n)
region around
charged objects that apply an electric force.
2.
is the force an electric field applies to another charged
object.
3. The electric force between two charged objects depends on the
of charge on the objects.
a. Two negative objects
each other away.
b. Two positive objects
each other away.
c. A positive object and a negative object
each other
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
together.
Electricity and Magnetism
11
Name
Date
Class
Content Practice A
LESSON 1
Electric Charges and Electric Forces
Directions: On the line before each definition, write the letter of the term that matches it correctly. Each term is
used only once.
1. refers to a particle that has equal amounts of
positive charge and negative charge
2. refers to an object that has an unbalanced
amount of positive charge or negative charge
3. refers to an object that has more positive charge
than negative charge
A. electric conductor
B. electric field
C. electric force
D. electric discharge
E. electrically charged
F. electrically neutral
4. refers to an object that has more negative charge
than positive charge
5. the loss of an unbalanced electric charge
G. electric insulator
H. negatively charged
I. positively charged
6. a material in which electric charges cannot easily
move
7. a material in which electric charges easily move
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
8. the force that two electrically charged objects
apply to each other
9. the invisible region around a charged object
where an electric force is applied
Electricity and Magnetism
13
Name
Date
Content Practice B
Class
LESSON 1
Electric Charges and Electric Forces
Directions: Distinguish between the terms in each of the following pairs.
1. atom, nucleus
2. proton, electron
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
3. positively charged, negatively charged
4. electric insulator, electric conductor
14
Electricity and Magnetism
Name
Date
Class
Key Concept Builder
LESSON 1
Electric Charges and Electric Forces
Key Concept How do objects become electrically charged?
Directions: Circle the term in parentheses that correctly completes each sentence.
1. (Atoms/Electric charges) are the tiny particles that make up all the matter
around you.
2. An atom has a(n) (nucleus/electron) that is made up of two kinds of smaller particles
called protons and neutrons.
3. (Electrons/Protons) move around an atom’s nucleus.
4. (Protons/Neutrons) do not have electric charge.
5. (Electrons/Neutrons) have electric charge.
objects become electrically charged.
7. Whether an object becomes positively or negatively charged depends on the material
it (repels/contacts).
8. Electrons transfer from a material that holds electrons (more/less) tightly to a material
that holds electrons (more/less) tightly.
9. Wool does not hold electrons as tightly as rubber, so when a wool sweater and a rubber
balloon are rubbed together, electrons transfer from the (sweater/balloon) to the
(sweater/balloon).
16
Electricity and Magnetism
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
6. When (protons/electrons) transfer from one electrically neutral object to another, the
Name
Date
Key Concept Builder
Class
LESSON 1
Electric Charges and Electric Forces
Key Concept How do electrically charged objects differ?
Directions: Complete the concept map with the correct term or statement from the word bank in the space provided.
Each term or statement is used only once.
An object has equal amounts of protons and electrons.
An object has more electrons than protons.
An object has more protons than electrons.
electrically charged
negatively charged
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Types of Charges
electrically neutral
positively charged
Electricity and Magnetism
17
Name
Date
Key Concept Builder
Class
LESSON 1
Electric Charges and Electric Forces
Key Concept How do electrically charged objects interact?
Directions: On the line before each item, write I if the substance is an electric insulator or C if the substance is an
electric conductor.
1. aluminum
2. paper
3. glass
4. iron
5. plastic
6. gold
7. copper
8. wood
9. rubber
Directions: Respond to each statement on the lines provided.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
10. Contrast electric insulators and electric conductors.
11. Will an electric charge spread over an entire balloon? Explain.
18
Electricity and Magnetism
Name
Date
Class
Key Concept Builder
LESSON 1
Electric Charges and Electric Forces
Key Concept How do electrically charged objects interact?
Directions: Answer each question in the space provided.
Question
Answer
1. What is an electric force?
2. What is an electric field?
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
3. How will two positively charged
objects interact?
4. How will two negatively charged
objects interact?
5. How will a negatively charged
object and a positively charged
object interact?
6. What can you infer about the
electric charges of two objects
that attract each other?
7. What can you infer about the
electric charges of two objects
that repel each other?
Electricity and Magnetism
19
Name
Date
Class
Lesson Quiz A
LESSON 1
Electric Charges and Electric Forces
Multiple Choice
Directions: On the line before each question or statement, write the letter of the correct answer.
1. A particle that has equal amounts of positive charge and negative charge is
A. positively charged.
B. electrically neutral.
C. negatively charged.
2. Which material is an insulator in which electric charges cannot easily move?
A. gold
B. plastic
C. aluminum
3. Which material is a conductor in which electric charges easily move?
A. wood
B. paper
C. copper
Matching
Directions: On the line before each definition, write the letter of the term that matches it correctly. Each term is
used only once.
24
5. the loss of an unbalanced electric charge
A. electric force
6. the push or pull between charged objects
B. electric discharge
7. the invisible region around any charged object
C. electric field
Electricity and Magnetism
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
4. How do objects become electrically charged?
A. Protons move from one object to another.
B. Neutrons move from one object to another.
C. Electrons move from one object to another.
Name
Date
Class
Lesson Quiz B
LESSON 1
Electric Charges and Electric Forces
Multiple Choice
Directions: On the line before each question or statement, write the letter of the correct answer.
1. A negatively charged particle has
A. more protons than electrons.
B. more electrons than protons.
C. neutrons and protons but no electrons.
D. an equal number of protons and electrons.
2. Which material is classified as an insulator?
A. iron
B. gold
C. plastic
D. aluminum
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
3. Which material is classified as a conductor?
A. glass
B. paper
C. wood
D. copper
4. When two objects touch, which object becomes negatively charged?
A. the object that has the greater mass
B. the object that loses electrons more easily
C. the object that has the smaller surface area
D. the object that holds electrons more tightly
Matching
Directions: On the line before each definition, write the letter of the term that matches it correctly. Not all terms
are used.
5. the loss of an unbalanced electric charge
A. electric force
6. the push or pull between charged objects
B. electrically neutral
7. the invisible region around any charged object
C. electrically charged
D. electric discharge
E. electric field
Electricity and Magnetism
25
Name
Date
Class
Lesson Outline
LESSON 2
Electric Current and Electric Circuits
A. Electric Current—Moving Electrons
1. The movement of electrically charged particles in one direction can occur in
a(n)
.
a. Because of their motion, moving electrons contain
energy.
b. As electrons move from atom to atom, this energy can transform into
or
energy.
2. Electric current can be either a(n)
current or an
alternating current.
a. An electric current that flows in only one direction is a(n)
current.
b. An electric current that frequently changes direction is
a(n)
current.
c. Most current used in homes and businesses is
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
current.
B. The Circuit—A Path for Electric Current
1. The path through which an electric current flows is called
a(n)
2.
.
circuits are found in flashlights, doorbells, and many
appliances.
a. Sources of energy can come from
, generators, solar
cells, and fuel cells.
b. chemical reactions within a battery move electrons from the
terminal to the
3. A circuit needs a device to
terminal.
electric energy to other
forms of energy.
a. Energy transformations occur when current flows through a circuit
that has
.
b. Electric resistance is a measure of how
it is for a
current to pass through a material.
Electricity and Magnetism
29
Name
Date
Class
Lesson Outline continued
c. Materials with
electric resistance transform more
electric energy into other types of energy, such as
4. A circuit also needs an electric
.
to carry the current to
an from the other components of the circuit.
a. Most conductors in a circuit are in the form of
.
b. A good conductor has low electric
.
5. Electric circuits can be
circuits, in which there is only
one path for the current to follow, or
contain more than one path for current.
circuits, which
C. Voltage and Electric Energy
1. The unit used for counting electrons in a circuit is the
2. The
.
of an electric energy source is the amount of
energy used to move a(n)
circuit.
of electrons through the
D. A Practical Electric Circuit
1. An electric circuit could contain a(n)
that allows you to
start or stop a device.
energy.
3. The circuit could also contain an electric
transforms electric energy into
, which
energy.
4. The circuit could contain a temperature-sensitive
switch that would automatically turn the device off if it becomes
dangerously
30
.
Electricity and Magnetism
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
2. The circuit could contain a heating device, which transforms electric energy into
Name
Date
Class
Content Practice A
LESSON 2
Electric Current and Electric Circuits
Directions: On the line before each definition, write the letter of the term that matches it correctly. Each term is
used only once.
1. the movement of electrically charged particles
A. alternating current
2. an electric current that continually flows in one
B. direct current
direction
3. an electric current that continually reverses
direction
C. electric circuit
D. electric current
E. electric resistance
4. a closed path in which an electric current flows
F. generator
5. the end of a battery from which electrons flow
G. negative terminal
6. the end of a battery into which electrons flow
H. positive terminal
7. a machine that transforms mechanical energy to
I. voltage
electric energy
8. a measure of how difficult it is for an electric
current to flow in a material
9. the amount of energy used to move one coulomb
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
of electrons through a circuit
32
Electricity and Magnetism
Name
Date
Class
Content Practice B
LESSON 2
Electric Current and Electric Circuits
Directions: On each line, write the term that correctly completes each sentence.
1. The movement of
charged particles is an electric current.
2. Portable devices such as flashlights often use
current.
3. A simple circuit needs a source of
such as a battery.
4. A simple circuit also needs a conductor such as a(n)
.
5. The positively charged end of a battery is called the
terminal.
6. The negatively charged end of a battery is called the
terminal.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
7. Generators transform
energy to
energy.
8. Copper and aluminum make good wires in electric circuits because they are
excellent
9. A(n)
.
is the unit used to count electric charges.
10. A high
reading means that an electric circuit is
transforming large amounts of energy.
Electricity and Magnetism
33
Name
Date
Language Arts Support
Class
LESSON 2
Writing Activity: Writing a Summary
A summary is a short version of a large amount of text. When you write a summary, you
use words to explain the main idea and details of a concept in simpler terms. Writing
summaries can help you understand complex concepts and communicate them to someone
who is not familiar with them.
When you read about the concept that you will be summarizing, pay attention to the
main idea of the text and the relevant details that you will need to include. Also note
unimportant details that you can leave out of your summary.
Directions: Reread the section in Lesson 2 of your textbook titled Series and Parallel Circuits. In your own words,
write a summary in the space provided.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
34
Electricity and Magnetism
Name
Date
Class
Language Arts Support
LESSON 2
Writing Activity: Creating a Concept Map
A concept map can help you understand the relationship between concepts. A concept map
connects terms, or concepts, using descriptions. To make a concept map, write the central
concept in the center of the paper. Add concepts to the map, connecting the terms using
descriptive phrases and making as many connections as possible. The example below
illustrates how to connect terms in a concept map.
parallel circuit
electric current
two types
path for
Electric Circuit
series circuit
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Directions: Make a concept map that includes the terms below. The central concept is written for you. You may
include additional terms or concepts in your concept map.
alternating current
battery
conductors
direct current
electric circuit
electrons
generator
insulators
negatively charged
Electric Current
Electricity and Magnetism
35
Name
Date
Class
Math Skills
LESSON 2
Using Fractions
Each device in a circuit transforms a portion of the source’s electric energy into other forms
of energy such as light and heat. To find the fraction of energy used by a device in the
circuit, divide the voltage reading across the device by the total voltage of the energy
source. The sum of all the fractions must add up to 1, the total energy in the circuit.
A 12-volt (V) battery is connected to two lightbulbs in a series circuit. The voltage reading
across the first lightbulb is 3 V. What portion of the battery’s energy transforms in the
second lightbulb?
Step 1 Find the fraction of energy transformed by the first lightbulb.
The lightbulb transformed 3 out of the 12 volts.
3V
3
1
_____
= ___
= __
4
12 V
12
Step 2 Write an equation. Remember that all the fractions must add up to 1.
1 +x=1
__
4
Step 3
Solve for the missing number. Any fraction that has the same number in the
numerator and denominator equals 1.
3
The second lightbulb transforms __
of the source’s energy.
4
Practice
1. A 12-V battery powers two lightbulbs
3. A 12-V battery powers three lightbulbs
in a series circuit. The voltage reading
across one lightbulb is 6 V. What
portion of the battery’s energy
transforms in the other lightbulb?
in a series circuit. The voltage reading
is 6 V across the first lightbulb and 3 V
across the second lightbulb. What
portion of the battery’s energy
transforms in the third lightbulb?
2. A 9-V battery powers three lightbulbs
in a series circuit. The voltage reading
across each lightbulb is 3 V. What
portion of the battery’s energy
transforms in each lightbulb?
36
4. An electric heater has an “on” light
and a heating element powered by a
120-V source. The voltage reading
across the “on” light is 1 V. What
portion of the battery’s energy
transforms in the heating element?
Electricity and Magnetism
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
3
1 = __
4 - __
1 = __
x = 1 - __
4
4
4
4
Name
Date
Key Concept Builder
Class
LESSON 2
Electric Current and Electric Circuits
Key Concept How are electric current and electric charge related?
Directions: Respond to each statement on the lines provided.
1. Compare an electric charge and an electric current.
2. Compare the kinds of devices that usually use direct current and alternating current in
the United States.
38
Electricity and Magnetism
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Directions: Draw how electrons move in a direct current and in an alternating current in the space provided. Use
symbols, labels, and arrows to label your drawing.
Name
Date
Class
Key Concept Builder
LESSON 2
Electric Current and Electric Circuits
Key Concept What are the parts of a simple electric circuit?
Directions: Answer each question or respond to each statement in the space provided.
Question
Answer
1. What is an electric circuit?
2. What are the parts of a simple
electric circuit?
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
3. Give an example of a source of
electric energy.
4. Explain how electrons move
through a battery.
5. Give an example of a conductor
used in an electric circuit.
6. Should a conductor have high or
low electric resistance? Explain.
7. Give an example of a device that
transforms electric energy in an
electric circuit.
8. What determines how much
electric energy flowing through a
circuit is transformed to other
forms of energy?
Electricity and Magnetism
39
Name
Date
Class
Key Concept Builder
LESSON 2
Electric Current and Electric Circuits
Key Concept How do the two types of electric circuits differ?
Directions: Write the correct term from the word bank on each line. Terms will be used more than once.
battery
conductor
lightbulb
switch
5.
1.
6.
2.
8.
4.
–
+
–
+
7.
3.
Figure A
Figure B
Directions: Use the diagram to answer each question on the lines provided.
10. How were you able to distinguish between the two circuits?
11. In the figures above, which parts are sources of energy?
12. Which parts are devices for transforming electric energy into another form of energy?
13. Which parts are the conductors?
40
Electricity and Magnetism
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
9. Which figure above shows a series circuit? Which one shows a parallel circuit?
Name
Date
Key Concept Builder
Class
LESSON 2
Electric Current and Electric Circuits
Key Concept How do the two types of electric circuits differ?
Directions: On the line before each statement, write T if the statement is true or F if the statement is false. If the
statement is false, change the underlined word(s) to make it true. Write your changes on the lines provided.
1. A series circuit is an electric circuit that has multiple paths that an
electric current can flow through.
2. All the devices in a series circuit are connected end-to-end.
3. Any break, or opening, in a parallel circuit causes the current to stop flowing
through the entire circuit.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
4. Houses use parallel circuits for their electrical needs.
5. A parallel circuit is an electric circuit that has only one path through which an
electric current can flow.
6. In a parallel circuit, each device connects to the electric source using a separate
path, or branch.
7. If you turn off one light in a parallel circuit, the other lights will remain lit.
8. Unlike series circuits, parallel circuits need sources of energy, conductors,
and devices for transforming electric energy to another type of energy.
Electricity and Magnetism
41
Name
Date
Class
Lesson Quiz A
LESSON 2
Electric Current and Electric Circuits
Completion
Directions: On each line, write the term from the word bank that correctly completes each sentence. Each term is
used only once.
electric circuit
electric current
generator
voltage
electric resistance
1. The movement of electrically charged particles is
2. A(n)
.
is a closed, or complete, path in which an electric
current flows.
3. A(n)
transforms mechanical energy to electric energy.
4.
is a measure of how difficult it is for an electric current to
flow in a material.
5. The amount of energy used to move one coulomb of electrons through the circuit is
its
.
Multiple Choice
Directions: On the line before each statement, write the letter of the correct answer.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
6. An electric current that continually flows in one direction is
A. a direct current.
B. a parallel current.
C. an alternating current.
7. The electric devices in most homes are a part of
A. a series circuit.
B. a parallel circuit.
C. an alternating circuit.
44
Electricity and Magnetism
Name
Date
Class
Lesson Quiz B
LESSON 2
Electric Current and Electric Circuits
Completion
Directions: On each line, write the term from the word bank that correctly completes each sentence. Not all
terms are used.
battery
chemical energy
electric circuit
electric current
electric resistance
generator
terminal
voltage
1. The movement of electrically charged particles is
2. A(n)
.
is a closed, or complete, path in which an electric
current flows.
3. A(n)
4.
transforms mechanical energy to electric energy.
is a measure of how difficult it is for an electric current to
flow in a material.
5. The amount of energy used to move one coulomb of electrons through the circuit is
its
.
Short Answer
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Directions: Respond to each statement on the lines provided.
6. Compare and contrast direct current and alternating current.
7. Differentiate parallel circuits and series circuits.
Electricity and Magnetism
45
Name
Date
Class
Lesson Outline
LESSON 3
Magnetism
A. What is a magnet?
1. Any object that attracts iron is a(n)
.
2. Iron is an example of a(n)
because a magnet attracts
iron.
B. Magnetic Fields and Magnetic Forces
1. A magnet is surrounded by an invisible
.
2. A push or pull that a magnet applies on a magnetic material is
a(n)
.
a. This force exists even if the objects are not
.
b. Magnetic field lines start on the
pole of a magnet
and end at the
pole.
3. Magnetic poles apply
.
a. Two poles of the same type
each other.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
b. A north pole and a south pole
each other.
4. Molten iron and nickel in Earth’s
cause Earth to act like
a giant magnet.
a. Earth has a magnetic north pole and a magnetic
.
b. Earth’s magnetic south pole is near Earth’s geographic
Pole.
C. Magnets
1. Atoms are grouped in
in some materials.
a. A magnetic domain is a region in a magnetic material in which the
of the atoms all point in the same direction.
b. The individual magnetic fields combine to form
magnetic field.
2. In nonmagnetic materials, the random magnetic fields cancel out the magnetic
of each other.
3. Some magnetic materials, such as iron and
grouped in
a. Not all magnetic materials are
Electricity and Magnetism
are
.
.
49
Name
Date
Class
Lesson Outline continued
b. If the magnetic domains point in the same direction, the material becomes
a(n)
.
4. Magnetic materials are known as either soft magnetic materials
or
.
a. Soft magnetic materials form
magnets.
b. Hard magnetic materials form
magnets.
D. Combining Electricity and Magnetism
1. The relationship between electricity and magnetism is
called
.
2. Electric current is produced when a(n)
and a wire
move past each other.
3. An electromagnet is a type of temporary magnet produced when a current-carrying
wire is wrapped around a(n)
core.
4. The magnetic field of an electromagnet can be turned on and off by turning the
on and off.
5. The strength of an electromagnet can be controlled by controlling the amount of
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
in the coil, or by the number of
in the coil.
50
Electricity and Magnetism
Name
Date
Content Practice A
Class
LESSON 3
Magnetism
Directions: On the line before each statement, write the letter of the correct answer.
1. An object that attracts iron is
A. a magnet.
B. a generator.
C. an electromagnet.
2. Any object that a magnet attracts is a magnetic
A. pole.
B. field.
C. material.
3. The push or pull that a magnet applies to another magnet or to an object made
of a magnetic material is a magnetic
A. field.
B. force.
C. domain.
4. The place on a magnet where the magnet exerts the strongest magnetic force
5. A group of atoms where the magnetic fields of the atoms point in the same
direction is
A. a magntic force.
B. an electromagnet.
C. a magnetic domain.
6. A temporary magnet made with a current-carrying wire coil wrapped around
a magnetic core is
A. a magnetic field.
B. an electromagnet.
C. a permanent magnet.
52
Electricity and Magnetism
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
is the magnetic
A. pole.
B. force.
C. domain.
Name
Date
Content Practice B
Class
LESSON 3
Magnetism
Directions: Explain the relationship that exists between each set of terms on the lines provided.
1. magnet, magnetic material
2. magnetic force, magnetic poles
3. magnetic field, magnetic domain
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
4. nonmagnetic material, magnet
5. soft magnetic material, hard magnetic material
6. temporary magnet, permanent magnet
7. generator, electromagnet
Electricity and Magnetism
53
Name
Date
Key Concept Builder
Class
LESSON 3
Magnetism
Key Concept What causes a magnetic force?
Directions: Answer each question on the lines provided.
1. What is a magnetic force?
2. How does distance affect the strength of the magnetic force?
3. What is a magnetic pole?
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
4. What are the two types of magnetic poles?
5. How do magnetic poles interact?
Directions: Draw arrows between each set of bar magnets to show whether the magnets will attract one another
(→←) or repel one another (←→). S represents the south pole, and N represents the north pole.
6.
7.
8.
9.
S
N
S
N
S
N
N
S
N
S
N
S
N
S
S
N
Electricity and Magnetism
55
Name
Date
Class
Key Concept Builder
LESSON 3
Magnetism
Key Concept How are magnets and magnetic domains related?
Directions: Use the diagram to answer each question on the lines provided.
Figure A
Figure B
S
S
N
S
S
S N
S N
N
N
S
N
S
N
S
N
S
S
N
S
N
S N
S N
S
S
N
S
N
S N
N
S
N
S
N
S
N
S
S N
N
S
S
N
N S
S
N
N
S
N
N
S
N
S N
S N
S
S
N
S
N
N
S
S
N
N N
S
S
N
N N N S
S N
S S
S N N S
S S
N
N
S
S
N
N
N
S
N N S
S
S S
N
N
S
N
N
N
S
S S
S
N
N
S S
Figure C
N
N
S
N
N
N S
S
N
N S
S
N
S
N
S
S
N
N S
S
N
N S
S
N
N S
S
N
N S
S
N
N S
N
N S
S
N
N S
S
N
N S
S
N
N S
S
N
N S
S
N
N S
S
S
N
S
N
N S
S
N
N S
S
1. What do the smallest circles represent in each of the three diagrams?
2. Which figure shows a nonmagnetic material? Use the concept of magnetic domains to
explain how you reached your answer.
explain how you reached your answer.
4. Which figure shows a magnet? Use the concept of magnetic domains to explain how
you reached your answer.
56
Electricity and Magnetism
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
3. Which figure shows a magnetic material? Use the concept of magnetic domains to
Name
Date
Class
Key Concept Builder
LESSON 3
Magnetism
Key Concept How are magnets and magnetic domains related?
Directions: On each line, write the term from the word bank that correctly completes each sentence. Each term
is used only once.
atoms
iron
magnetic domains
magnetic field
magnetic materials
magnets
nonmagnetic materials
plastic
All materials are made of (1.)
A(n) (2.)
(3.)
.
surrounds each atom. Some atoms are grouped into
, which means that the magnetic fields of the groups of
atoms are aligned.
The atoms of materials such as (4.)
are not grouped in
magnetic domains. These materials are (5.)
. The atoms of
materials such as (6.)
are grouped into magnetic domains. If
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
the magnetic domains point in random directions, then the materials are
(7.)
. If the magnetic domains point in the same direction, then
the materials are (8.)
.
Directions: Answer each question on the lines provided.
9. Is a nail a soft magnetic material or a hard magnetic material? Explain.
10. What happens to the magnetic domains of a nail when it is placed near a magnet? Is
the nail a magnet? Explain.
11. What happens to the magnetic domains of a nail when it is placed far from a magnet?
Is the nail a magnet? Explain.
Electricity and Magnetism
57
Name
Date
Class
Key Concept Builder
LESSON 3
Magnetism
Key Concept How are electric currents and magnetic fields related?
Directions: Circle the term in parentheses that correctly completes each sentence.
1. The relationship between electricity and magnetism is called
(electric current/electromagnetism).
2. A generator can produce an electric current by passing a wire coil through a magnetic
(field/domain).
3. If the wire coil in a generator connects to a(n) (closed/open) circuit, then electric
charges move through the circuit as the magnet moves past the wires.
4. If the magnet in the generator (begins/stops) moving, the electric current stops flowing.
5. If a current-carrying wire forms a coil, then the magnetic field around the wire becomes
6. If a (hard/soft) magnetic core is placed within the coil formed by a current-carrying
wire, then the magnetic field around the wire becomes stronger.
7. An electromagnet is a (temporary/permanent) magnet made with a current-carrying
wire wrapped around a soft magnetic core.
8. The magnetic field of an electromagnet (can/cannot) be turned off and on using the
current in the coil.
9. The north and south poles of an electromagnet (reverse/stay the same) if the current
reverses.
10. The strength of a(n) (magnet/electromagnet) can be controlled by the number
of windings in the coil and the amount of electric current in the coil.
58
Electricity and Magnetism
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
(stronger/weaker).
Name
Date
Class
Lesson Quiz A
LESSON 3
Magnetism
Matching
Directions: On the line before each definition, write the letter of the term that matches it correctly. Each term is
used only once.
1. a group of atoms with magnetic fields
pointing in the same direction
2. a push or pull exerted by a magnet
A. magnetic force
B. magnetic material
C. magnetic domain
3. a substance that a magnet attracts
True or False
Directions: On the line before each statement, write T if the statement is true or F if the statement is false. If the
statement is false, change the underlined word(s) to make it true. Write your changes on the lines provided.
4. A current-carrying wire is surrounded by a magnetic field.
5. Iron is a material attracted by magnets.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
6. If two like magnetic poles are next to one another, the magnets attract one
another.
7. Nonmagnetic materials have atoms grouped in domains that point in random
directions.
8. Temporary magnets are made of hard magnetic materials.
Electricity and Magnetism
61
Name
Date
Class
Lesson Quiz B
LESSON 3
Magnetism
Matching
Directions: On the line before each definition, write the letter of the term that matches it correctly. Not all terms
are used.
1. a group of atoms that has magnetic fields
pointing in the same direction
A. electromagnet
B. magnetic force
2. a push or pull exerted by a magnet
C. magnetic pole
3. a substance that a magnet attracts
D. magnet
4. an object that attracts iron
E. magnetic material
5. surrounds a current-carrying wire
F. magnetic field
G. magnetic domain
Short Answer
Directions: Respond to each statement on the lines provided.
6. Define magnetic pole and explain how magnets interact when their like poles are
placed next to one another.
8. Explain how the materials that make up temporary magnets and permanent magnets
differ.
62
Electricity and Magnetism
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
7. Describe the arrangement of atoms in a magnetic material.
Lesson Outline for Teaching
Lesson 1: Electric Charges and Electric Forces
A. Electric Charges
Lesson Outline continued
the objects.
3. The electric force between two charged objects depends on the type of charge on
a. Two negative objects push each other away.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
b. Two positive objects push each other away.
1. Each atom contains a core called the nucleus.
c. A positive object and a negative object pull each other together.
C383_082_087_CRF_AnsOut_892505.i83 83
Electricity and Magnetism
6/22/10 11:27:23 AM
T3
As clothes rub against each other, electrons are transferred, and the items become charged.
Opposite items attract each other. On cold days there are fewer water molecules in the air
to accept charges from the charged items.
Why do clothes stick to each other when you take them out of the dryer on a cold, dry
day?
Discussion Question
a. The nucleus is made up of smaller particles called protons and neutrons.
6/22/10 11:27:22 AM
b. Atoms also contain electrons which move around the nucleus.
c. Protons and electrons have electric charge.
a. Protons have positive charge; electrons have negative charge.
2. Electric charges are either positive or negative.
b. Atoms are electrically neutral because they have equal amounts of positive and
negative charges.
electrons.
c. Electrically neutral objects become electrically charged when they gain or lose
d. An object that loses electrons becomes positively charged.
e. An object that gains electrons becomes negatively charged.
3. Electric discharge is the loss of unbalanced electric charge by an object.
static cling lasts longer on dry days.
a. Some electric discharge occurs slowly, for example, maybe you have noticed that
b. A lightning strike is an example of an electric discharge that occurs quickly.
4. Electric charges move at different rates through different materials.
a. Materials through which electric charge moves easily are called electric conductors.
insulators.
b. Materials through which electric charge cannot move easily are called electric
c. Examples of insulators include plastic, wood, and glass.
d. Some of the best conductors of electric charge are metals.
B. Electric Fields and Electric Forces
a. Charged objects do not have to touch to exert a force on each other.
1. An electric charge is surrounded by a(n) electric field.
apply an electric force.
b. Scientists know that there is a(n) invisible region around charged objects that
Electricity and Magnetism
2. Electric force is the force an electric field applies to another charged object.
C383_082_087_CRF_AnsOut_892505.i82 82
T2
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Lesson Outline for Teaching
Lesson 2: Electric Current and Electric Circuits
A. Electric Current—Moving Electrons
1. The movement of electrically charged particles in one direction can occur in a(n)
conductor.
a. Because of their motion, moving electrons contain kinetic energy.
thermal energy.
b. As electrons move from atom to atom, this energy can transform into light or
a. An electric current that flows in only one direction is a(n) direct current.
2. Electric current can be either a(n) direct current or an alternating current.
b. An electric current that frequently changes direction is a(n) alternating current.
c. Most current used in homes and businesses is alternating current.
B. The Circuit—A Path for Electric Current
1. The path through which an electric current flows is called a(n) electric circuit.
a. Sources of energy can come from batteries, generators, solar cells, and fuel cells.
2. Simple circuits are found in flashlights, doorbells, and many kitchen appliances.
the negative terminal.
b. chemical reactions within a battery move electrons from the positive terminal to
3. A circuit needs a device to transform electric energy to other forms of energy.
electric resistance.
a. Energy transformations occur when current flows through a circuit that has
a material.
b. Electric resistance is a measure of how difficult it is for a current to pass through
types of energy, such as light.
c. Materials with high electric resistance transform more electric energy into other
other components of the circuit.
4. An circuit also needs an electric conductor to carry the current to and from the
a. Most conductors in a circuit are in the form of wires.
b. A good conductor has low electric resistance.
Electricity and Magnetism
5. Electric circuits can be series circuits, in which there is only one path for the
current to follow, or parallel circuits, which contain more than one path for
current.
1. The unit used for counting electrons in a circuit is the coulomb.
C. Voltage and Electric Energy
T4
6/25/10 7:31:41 PM
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
C383_082_087_CRF_AnsOut_892505.i84 84
Lesson Outline continued
coulomb of electrons through the circuit.
2. The voltage of an electric energy source is the amount of energy used to move a
D. A Practical Electric Circuit
device.
1. An electric circuit could contain a(n) switch that allows you to start or stop a
thermal energy.
2. The circuit could contain a heating device, which transforms electric energy into
into mechanical energy.
3. The circuit could also contain an electric motor, which transforms electric energy
automatically turn the device off if it becomes dangerously hot.
4. The circuit could contain a temperature-sensitive cutoff switch that would
Discussion Question
What devices in your home use direct current? What devices use alternating current?
T5
6/22/10 11:27:25 AM
Sample answer: Devices that use direct current include those that use batteries, such as
flashlights, cell phones, and hand-held video games. Devices that use alternating current
are those that plug into outlets, such as washing machines, televisions, and lamps.
Electricity and Magnetism
C383_082_087_CRF_AnsOut_892505.i85 85
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Lesson Outline for Teaching
Lesson 3: Magnetism
1. Any object that attracts iron is a(n) magnet.
A. What is a magnet?
2. Iron is an example of a(n) magnetic material because a magnet attracts iron.
1. A magnet is surrounded by an invisible magnetic field.
B. Magnetic Fields and Magnetic Forces
a. This force exists even if the objects are not touching.
2. A push or pull that a magnet applies on a magnetic material is a(n) magnetic force.
b. Magnetic field lines start on the north pole of a magnet and end at the south
pole.
a. Two poles of the same type repel each other.
3. Magnetic poles apply forces.
b. A north pole and a south pole attract each other.
a. Earth has a magnetic north pole and a magnetic south pole.
4. Molten iron and nickel in Earth’s core cause Earth to act like a giant magnet.
b. Earth’s magnetic south pole is near Earth’s geographic North Pole.
materials.
a. Soft magnetic materials form temporary magnets.
b. Hard magnetic materials form permanent magnets.
Electricity and Magnetism
4. Magnetic materials are known as either soft magnetic materials or hard magnetic
magnet.
b. If the magnetic domains point in the same direction, the material becomes a(n)
a. Not all magnetic materials are magnets.
3. Some magnetic materials, such as iron and steel are grouped in magnetic domains.
effects of each other.
2. In nonmagnetic materials, the random magnetic fields cancel out the magnetic
b. The individual magnetic fields combine to form one magnetic field.
fields of the atoms all point in the same direction.
a. A magnetic domain is a region in a magnetic material in which the magnetic
1. Atoms are grouped in magnetic domains in some materials.
C. Magnets
T6
6/22/10 11:27:25 AM
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
C383_082_087_CRF_AnsOut_892505.i86 86
Lesson Outline continued
1. The relationship between electricity and magnetism is called electromagnetism.
D. Combining Electricity and Magnetism
other.
2. Electric current is produced when a(n) magnet and a wire coil move past each
wrapped around a(n) magnetic core.
3. An electromagnet is a type of magnet produced when a current-carrying wire is
electric current on and off.
4. The magnetic field of an electromagnet can be turned on and off by turning the
electric current in the coil, or by the number of loops in the coil.
5. The strength of an electromagnet can be controlled by controlling the amount of
Discussion Question
How might an electromagnet be helpful in a recycling center?
6/22/10 11:27:26 AM
T7
Sample answer: The electromagnet could separate cans containing iron from other
recyclable materials. The magnet could move the cans to a separate location; then the cans
could be dropped there by stopping the flow of electric current in the electromagnet.
Electricity and Magnetism
C383_082_087_CRF_AnsOut_892505.i87 87
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.