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Electricity and Magnetism for Freshmen
Physical Science

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David N. Dean

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6/01 cJClRCJDateDuopGS-nt 5

ELECTRICITY AND MAGNETISM FOR FRESHMEN PHYSICAL SCIENCE
By

David N. Dean

A THESIS

Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of

MASTER OF SCIENCE
Division of Science and Mathematics Education

2002

ABSTRACT
ELECTRICITY AND MAGNETISM FOR FRESHMEN PHYSICAL SCIENCE
By

David N. Dean

The goal of this unit was to implement engaging lessons and activities relating
electricity and magnetism in order to enhance the learning environment for these topics.
Students taking Physical Science did not appear to have to have a good understanding of the
basic concepts of electricity and magnetism, such as the relationships between current,
voltage and resistance, the different types of circuits, or the relationship between magnetism,
motors, generators and transformers. Altering the curriculum to offer students investigative
experiences in order to help them understand the principles of electricity and magnetism
became the focus of this research. By way of hands-on activities and experimentation,
students would be able to directly observe and determine properties relating current, voltage
and resistance within circuits and the interactions between magnets and electricity using

motors, generators and transformers.

TABLE OF CONTENTS

List of Tables ........................................................................................................ v
List of Figures ...................................................................................................... vi
Introduction .......................................................................................................... 1
Scientific Background .............................................................................. 5
Demographics .......................................................................................... 9
Implementation of the Electricity and Magnetism Unit ...................................... 11
Summary of Activities ............................................................................ 16
Evaluation
Overview from Journal Entries ............................................................... 20
Qualitative Data ...................................................................................... 25
Quantitative Data .................................................................................... 26
Discussion ........................................................................................................... 32

Appendices A: Learning Styles Information

9:59P?

Multiple Intelligence: Seven Styles of Learning .......................................... 35
Multiple Intelligence Evaluation Questions: What Kind of Learner M.I.?..36
The Multiple Intelligence Inventory: Student Score Sheet .......................... 38
Multiple Intelligence: Classroom Strategies ................................................ 39
Multiple Intelligence Assessment Menu ..................................................... 4O
Appendices B: Electricity and Magnetism Unit Student Work
Activity 1: Creating a Circuit ..................................................................... 42
Activity 2: Drawing a Circuit ..................................................................... 44
Activity 3: Circuits - Relating Voltage & Current ..................................... 46
Homework #1 Drawing Series Circuits ..................................................... 48
Class Warm-up 1: Circuits & Ohm’s Law .............................................. 49
Activity 4: Series Circuits - Ohm’s Law Calc .......................................... 50
Class Warm-up 2: The Light Bulb as a Circuit ......................................... 54
Activity 5: Drawing a Parallel Circuit ...................................................... 55

WHQMPPN!‘

iii

9. Class Warm-up 3: Drawing Parallel Circuits ............................................. 57

10 Activity 6: Draw & Wire Parallel Circuits ................................................ 58
11. Activity 7: Resistance ............................................................................... 63
12. Activity 8: Drawing Circuits & Using Ohm’s Law .................................. 64
13. Homework #2: Circuits & Ohm’s Laws .................................................. 67
14. Activity 9: Magnets .................................................................................. 70
15. Activity 10: Strength of Magnets ............................................................. 72
16. Activity 11: Magnetic Materials .............................................................. 73
17. Activity 12: Magnets & Magnetic Fields ................................................. 77
1 8. Activity 13: Electromagnets ..................................................................... 81
19. Activity 14: How a Motor Works ............................................................ 83
20. Class Warm-up 4: Rotating Motors ......................................................... 88
21. Activity 15: How Fast Does a Motor Turn .............................................. 89
22. Activity 16: Introduction to Transformers .............................................. 92
23. Activity 17: Transforms & Voltage ......................................................... 93
24. Homework #3: Unit Review .................................................................... 95
25. Unit 4 TEST ............................................................................................. 99
26. Student Survey ....................................................................................... 105
References ............................................................................................................... 107
General References ................................................................................................. 108

iv

LIST OF TABLES

Table 1: Percentage of students ranked in each learning style category ....... 3
Table 2: Number of Students Per Class Period .......................................... 10
Table 3: Average Test Score and Percent by Class Period and Gender ..... 24

Table 4: Electricity and Magnetism Unit Test Scores for
Physical Science classes in 2000 to 2002 ............................ 27

Figure 1:
Figure 2:
Figure 3:

Figure 4:

Figure 5:

Figure 6:

Figure 7:

Figure 8:

LIST OF FIGURES

Drawing of student circuit board ................................................ 11
Circuit diagram symbols ............................................................. 14
Circuit diagram and drawn circuit on student circuit board ....... 14

Bar graph comparing percentage test scores over three years
for the electricity and magnetism unit test ............................ 27

Bar graph showing the total score for each hour and the
average score on each objective on the

Electricity and Magnetism Test ............................................ 28

Bar graph showing the percentage of students scoring
correct responses on objective 1 questions ........................... 29

Bar graph showing the percentage of students scoring
correct responses objective 2 questions ................................ 30

Bar graph showing the percentage of students scoring
correct responses objective 3 questions ................................ 31

vi

Introduction

Physical Science classes at Mattawan High School have mainly utilized the textbook
and a few standard laboratory activities to show students, in a very short unit, the basics of
electricity and magnetism. This creates a challenge for both the students and teachers, since
electricity and magnetism tend to be topics covered at the end of the semester with very little
emphasis placed on student comprehension or the relationship between the aforementioned
phenomena. The students are “shutting down”, allowing their grades to slip, while the
teachers are desperately attempting to hold each student’s attention, keep them engaged and
cover as much material as possible. With this in mind, it seemed advantageous to implement
an electricity and magnetism unit with more engaging lessons and activities in order to
enhance the learning environment.

The implementation of an activity-based science curriculum engages students and
challenges them to construct scientific knowledge and understanding through
experimentation and inquiry. Problem solving, experimentation and investigation empower
students with greater freedom while providing a process that teachers can use to guide and
lead students. This transfers the active role in the classroom to the students through
problems and situations that connect to their lives (Delisle, R. 1997). Through recent brain
research and studies conducted by Howard Gardner pertaining to various learning styles, it
has been determined that individual students perceive and process information differently.
The old paradigm of how students acquire knowledge has changed. Gardner’s theory of
multiple intelligences gives educators an understanding of how the learning process differs
from one student to another. Traditional views of intelligence offered only the two basic
categories of analytical and verbal learning. Governed only by these two categories of

information processing, students were thought to be able to learn all the different types of

subject matter. Gardner challenges this idea of most students fitting neatly into only two
modes of intelligence and instead has identified as many as nine different intelligences or
learning styles. Gardner further speculates that there will be more learning styles identified
in the future (Gardner, H. 2000).

Over the seven years that I have evaluated the learning styles or multiple intelligences
of my students, I have identified only the seven original learning styles outlined by Gardner,
as found in Appendices A. As we change students at the beginning of each semester,
students entering my Physical Science classes are asked to complete a learning style
inventory to determine each individual’s learning style or styles. Thirty-five statements are
read outlining Gardner’s seven different intellegences or learning styles, five statements
describing some attribute of each learning style. The students are asked to respond by noting
the statements that they feel best describe them. During the class discussion that follows the
students share their ideas and questions about the individual tendencies that are common for
each learning style. Over the seven years that I have used an evaluation of learning styles,
the vast majority of my students have expressed a positive sense of agreement with the
outcome of the evaluation and have seemed to appreciate the insight it offers them about
themselves as a learner.

Frequently throughout the semester students are reminded to look back at the analysis
of their learning styles to reemphasize the manner in which they interact during learning
opportunities. Active involvement during class activities allows students to draw upon their
natural learning strengths. Since a majority of students show a strong tendency toward the
visual/spacial and bodily/kinesthetic learning styles, active hands-on assignments and small
group interaction should greatly improve the understanding and retention of information.

Table 1 shows the results of the learning styles inventory for the sixty-two Physical Science

students that took part in this study.

 

 

 

 

 

 

 

 

 

 

 

Table 1: Percentage of students identifying with each learning style category.

1.....- .. mm... $32321” ”It???”
Verbal/Linguistic 12.9% 50.0% 37.1%
Mathematical/Logical 1 1.3% 35.5% 53.2%
Visual/Spatial 54.8% 29.1% 16.1%
Bodily/Kinesthetic 66.1% 22.6% 1 l .3%
Musical/Rhythmic 79.0% 19.4% 1.6%
Interpersonal 35.5% 32.2% 32.3%
Intrapersonal 29.0% 33.9% 37.1%

 

 

 

 

As an educator, I feel it is important for students to actively participate in their
education and take responsibility for acquiring the knowledge and understanding deemed
necessary to be scientifically literate in today’s society. In my class, approximately 80
percent of a student’s grade is determined fi'om tests and assessments. It is my feeling that
a list of objectives offers each student a target with which to focus their efforts toward
learning what is expected and what will be tested. It is my general policy, and in this study,
that most activities are not graded but serve as the means for student to gain the knowledge,
experience and understanding that is expected. Homework assignments are given in order
for each student, along with me, to evaluate their level of comprehension of the topic covered
and whether or not extra assistance is needed.

Activities are either chosen or designed to be the means by which students can
experience and construct knowledge about the topics we cover in Physical Science. Through

a constructive approach, students are given multiple opportunities during class activities to

use laboratory equipment that allows them to test and explore the concepts outlined in the
objectives. Many of the activities have been designed or chosen in order for students to work
in small groups or individually and raise questions that can be tested by the students in order
to construct knowledge and understanding of magnetism and electricity. Students often need
to refocus and emphasize to them the purpose of completing the activities is to learn and
understand the science concepts rather than just a “play time” with the lab equipment. Dale
Parnell (1995) notes that many secondary classrooms are filled with students and labeled as
to the different subjects which will be “taught” within these walls. Teachers attempt to fill
each student’s head with bits of knowledge by way of lecture and textbooks with the idea
that they “might need it someday”. The process of solving problems, testing ideas and
discovering how things work is much more vital to a student’s education and understanding
than is note taking and remembering facts.

Multiple activities increase the retention of the information through repeated
experiences that help to focus the students on specific topics related to the objectives. Class
warm-ups are handouts used at the beginning of the class period to reinforce and review
terms and concepts correlated with the unit objectives in order to improve learning and
retention. The warm-up sheets give students an opportunity to take a few minutes to focus
on the terms or concepts that they have been working on during previous days activities. As
students complete the warm-ups, there is some class discussion in order to address any new
questions students may have before moving on with that day’s activities. Understanding and
applying scientific terminology and concepts are necessary for the retention of new and
existing information. Repeated rehearsals assist in this knowledge and application process
by ensuring students’ understanding of the unit concepts. In order for new learning to have

meaning and make sense, the learner must have time in order to process and reprocess new

information. In order for students to communicate scientifically, they must be able to
properly apply terminology and concepts. This rehearsal of information is the crucial part
of a continuous processing that is necessary for transfer learning to occur and for information
to be shifted from working memory to long-term storage (Sousa, D. A. 2001).

Constructing a solid understanding of the concepts being taught and forming
relationships between various concepts involves using a wide variety of methodology and
challenging students at the appropriate level with realistic expectations. For this to occur it
is important to maximize the efforts of both educators and students. The thought of holding
the attention of each student throughout the entire class period is unrealistic and has even
been proven to be less beneficial than having periods of high and low levels of attention
through peak interest activities and downtime reflection and processing (Jensen, E. 1998).
Scientific Background

Static electricity is a build up of electrons on the surface on an object. Electrons

can be deposited on objects such as a fiiction rod or Styrofoam cup when the surface is
rubbed over materials such as animal fur, wool or silk. As the rod or cup is rubbed on the
fur, loosely held electrons are picked up by the object causing its surface becomes “charged”
due to the accumulation of electrons on the object’s surface. When the negatively charged
object is brought near a foil leaf electroscope a positive charge is induced at the knob as the
electrons migrate away from the knob and downward into the foil leaves. This creates the
repulsion observed between the foil leaves suspended in the electroscope flask. When a
negatively charged Styrofoam cup is brought near to a second uncharged Styrofoam cup, the
second cup is repelled with enough force that the negatively charged cup is able to push the
other cup across the table without making contact.

Due to high humidity situations, the surface of obj ects can become more conductive

and will not allow a buildup of electrons. The water molecules in the air make the surfaces
conductive enough so that the moisture creates a "sho " on surfaces that would normally
collect electrons. Under high-humidity conditions, insulating surfaces can behave as a dead
short, almost like metal (Beaty, W. J ., 1994).

Electrical current is the flow of charges through a conducting material and is
measured in arnperes (amps). The force causing the charges to move is potential difference
or voltage measured in volts. Flow of charge can be regulated by the resistance, a property
of materials that resists or opposes the flow of charge through a material. Resistance is
measured in units of ohms. Metals are generally known to act as conductors and are used
to complete electrical circuits. Nonmetal materials commonly act as insulators due to the
fact that they block the flow of current. Among the three quantities of current, voltage, and
resistance, the relationship can be expressed mathematically using Ohm’s law which states
that the current through a conductor is directly proportional to the potential difference and
inversely proportional to the resistance. Different materials have different values for
resistance.

A circuit is a closed path allowing current to flow from place to place. Circuits can
be closed or open and classified as series or parallel. When a circuit is complete and permits
electric current to flow it is called a closed circuit. Closed circuits are commonly attributed
to situations that have a closed switch, referring to when the switch is in the “on” position.
An Open circuit is a condition that does not allow the flow of current to occur and frequently
is attributed to when the switch is in an open or “off” position. Series circuits have a single
path in which current flows through each individual part within the circuit. When any part
of a series circuit is removed or disabled the entire circuit is opened and the flow of

electricity stops. Parallel circuits have more than one path available for current to flow

through. The multiple paths in a parallel circuit allow different parts of the circuit to act
independently of each other. For instance, light switches in different rooms of a house or
switches within the same room are generally wired parallel. If a part of a parallel circuit is
removed or disabled, the parts of the circuit that are parallel to the removed or disabled parts
are still closed and the electricity flow is not altered. Most circuits used in household wiring
situations are combinations of series segments wired parallel to each other allowing each
segment of a circuit to act independently from other segments, such as the different circuits
observed in a firse box.

The phenomenon of magnetism has been observed for centuries. More than 2000
years ago the invisible magnetic fields of natural magnets, or loadstones, were observed
creating a force of attraction and repulsion making magnetism a puzzle. Magnetism is a
property of matter that produces a force of attraction or repulsion between objects that are
considered to be magnets. In order for magnetism to occur within a substance, groups of
atoms, called domains, align their magnetic poles with each pointing in the same direction.
Magnetic substances, such as iron, cobalt and nickel are attracted to a permanent magnet due
to the ability of their domains to line up when in the close proximity to a magnet. So, when
a permanent magnet is brought close to a magnetic substance the domains in the object align
and the substance is attracted to either end of the magnet and the magnetic substance
becomes a temporary magnet. When the permanent magnet is removed from the magnetic
field around one of the magnetic substances, the arrangement of the domains within the
object return to their previous random order and the substance no longer acts as a magnet.
The law of magnetism says that opposite poles of a magnet will be attracted to each other
and similar poles repel each other. A substance that is magnetic will be attracted to either

pole of a magnet. Magnets are strongest at their poles showing a greater attraction at their

poles than anywhere else along the magnet.

The property of magnetism can be used to do work by using the attraction and
repulsion properties of magnets to cause motion. When magnets are aligned in such a way
that their attraction and repulsion cause rotation; we call this a motor. A motor uses
electrical energy to create electromagnets that have the ability to alternate the direction of
their poles. A coil of wire that is wrapped around an iron core creates an electromagnet, or
temporary magnet, when current flows through the wire. The magnetic fields of the
electromagrrets interact with alternately aligned magnets attached to the rotor or rotating axle
within the motor. When the electromagnet and a permanent magnet on the rotor align so that
like poles are facing each other, the repelling force causes the rotor to rotate and the next
magnet, oriented with its poles in an opposite direction to the previous magnet, will then be
attracted to the electromagnet. The electromagnet is therefore repelling one magnet and
attracting the next. When the second magnet aligns with the electromagnet the current is
reversed and the poles of the electromagnet reverse their direction and the electromagnet now
repel the magnet that it was previously attracting. This repeated cycle within the motor is
the conversion of electrical energy to mechanical energy that can be used to do work.

Generators act opposite to motors and are turned mechanically to produce an
electrical current. Using electromagnets, a generator produces a magnetic field around the
rotating coil of wire found inside the generator that exerts a force on the electrons within the
wires, thus inducing a current to flow within the wire. Attaching a generator to a circuit
allows the current to flow to areas where electrical energy is needed.

The properties of electromagnetism and electromagnetic induction are used in
transformers to change the voltage of alternating current. A transformer is made of an iron

core with two coils of wire wrapped around it at two different locations. One side has an

incoming current and the opposite side has the resulting outgoing current. The coil of wire
carrying the incoming current on a transformer is called the primary coil, and the outgoing
coil is called the secondary coil. Electric current passing through the wire of the primary
coil induces the iron core to become an electromagnet which puts a force on the electrons in
the secondary coil causing current to flow in the wire of the secondary coil. Transformers
have the ability to increase voltage in what is called a step-up transformer, or to decrease
voltage in a step-down transformer. Step-up transformers are commonly used at power
plants to increase the voltage to high values and step-down transformers are located near
homes where the voltage needs to be decreased to lower values. Step-down transformers are
commonly used to reduce the voltage for portable CD players and small battery powered
devices around the home.
Demographics

This study conducted at Mattawan High School with freshman students enrolled in
Physical Science. Mattawan High School is a Class A high school having a student
population of roughly 1050 students, and a staff of teachers, administrators, and support staff
totaling 88 people located in Mattawan, Michigan. The school district encompasses
Mattawan, a small rural village, and the surrounding suburban areas located southwest of
Kalamazoo. Most residents work outside the general area of the school district and commute
to and from work. Of the sixty-two students participating in this study, sixty—one were
freshmen and one was a sophomore; thirty-one were boys and thirty-one were girls; three
were Hispanic students, one was an Asian student and one an Afiican-American student.
There is very little ethnic diversity in the Mattawan school system and the majority of the
students come from middle to upper-class homes with parents having a professional

background and higher education. The Physical Science course is the first of two science

courses required to graduate from Mattawan High School. Other than students who
successfully test out of Physical Science, all incoming ninth grade students are enrolled in
the course for their freshman year in high school. Students are varied in their academic
abilities and their motivation to do well in school. For example, the mathematics
experiences of the students in this study ranged from Pre-Algebra 1+, the lowest level math
course offered at Mattawan High School, all they way up to Advanced Algebra for the few
students that excelled in math. The sixty-two students involved in this study were split up

into three different sections throughout the school day as shown in Table 2.

f”. 2 -1Wrb3dems WP

    
      

 

Girls | Boys
12 7 12 12 7

 

 

 

 

 

 

Implementation of the Electricity and Magnetism Unit

When the Mattawan science staff analyzed proficiency test scores for 1997 through
1999, the electricity and magnetism cluster questions had a lower percentage of correct
responses than the motion and mechanics cluster questions. Students showed a lack of
understanding regarding the fundamental properties of electricity. With these things in mind,
I chose to design a unit on electricity and magnetism utilizing hands-on activities and
experiences which allowed students to observe and encounter properties of circuits, magnets,
motors, generators and transformers in situations that would be part of their everyday lives.
At the completion of the unit, students should recognize that common appliances around
their homes use the same principles and devices as those studied in class.

Through activities and demonstrations developed and planned during and since my
research in the summer of 1997, students experienced static and current electricity, circuits,
motors and generators. The electricity and magnetism unit was introduced fourteen weeks
into the second semester and completed over the last four weeks of the school year. The
previous units covered in the Physical Science course were motion, mechanics and energy.
During my research, my colleagues and I determined that we all had experiences with
different circuit activities that caused frustration for students. Too often students would
struggle to organize simple circuits using battery holders, miniature light fixtures and
switches. Using loose, individual circuit pieces tended to create a confusing situation for
students. Loose parts became spread out and mixed up, as well as wires getting twisted up
or clumped together making it almost impossible for students to recognize the circuits they
were wiring. If it was important for students to learn by observing and manipulating

circuits, then it was also important for them to have a set of circuit parts that were organized

ll

in a way that would allow them to more easily wire and experiment with different circuits.

Circuit boards, as seen in Figure 1, were assembled which worked very well for the students.

 

There was less confusion as students

connected and disconnected wires to

create different circuit configurations. $4 Bulbs & 2 Switches ’
FIT

L

In r arin to teach the
pep g ; 3Batte Holdes

    

electricity and magnetism unit, I

 

 

decided to keep a journal, allowing me

 

 

to address issues brought up by students

 

. . . . Figure 1: Drawing of student circuit board
during act1v1t1es and/or make

improvements or changes. I have found the journal to be personally gratifying and helpful,
making me more aware of each student’s abilities, questions and concerns. Keeping a
journal was something different for me and I hoped it would offer some insight into ways
that lessons might be changed and improved due to the student responses and interactions.
As a teacher, I generally found myself making “mental” notes (without writing them down)
about how activities went, or comments that were overheard among students as they worked
through an activity. These frequently were forgotten. Occasionally, I would remember
comments or my thoughts that occurred during class, then I would sit at the computer and
make corresponding changes to the activities. When making journal entries, I frequently
noted students’ comments, their attempts and reactions to the challenges they faced during
the various activities and comments they brought up during class discussions. Repeatedly,
I recorded my own insights, recognizing different ways that I could approach the same topic
with different groups of students. Changes that would improve the students’ comprehension

of concepts or the communication of the lessons were also noted. Not only did the journal

12

entries prove to be very interesting, it was also informative as I worked with three different
class periods throughout each day.

At the start of the electricity and magnetism unit a list of obj ectives was given to each
student. It is my practice, and my educational philosophy, to lay out the objectives for
students at the beginning of each unit. It is important for students to be cognizant of the
material that will be covered and the knowledge they are expected to acquire as they work
through the different activities and assignments. Students use the list of objectives as an
introduction to the material as they begin learning the information and as a study guide to
focus their learning. As the unit is completed, students return to the list of objectives to
review and summarize their ideas and experiences for the unit test.

In the electricity and magnetism unit, students are given the following objectives
based on the Michigan Curriculum Framework Science Benchmarks:

Objective #1: The student will be able to defineelectricity, in terms of circuits, and discuss
the relationship among voltage, current, and resistance within different circuits and
calculating values within a circuit using Ohm’s law.

Objective #2: The student will be able to identify parts within an electrical circuit, diagram
and construct circuits, and identify properties associated with series and parallel circuits.
Objective #3: The student will be able to describe how magnetism, magnetic fields and
magnetic poles interact and how they relate to motors, generators, and transformers.

Actively involved in small groups, students had opportunities to experiment and
observe properties of multiple circuit configurations making measurements utilizing

batteries, bulbs and switches, experimenting with magnets and relating their properties with

13

working motors, generators and transformers. Throughout the electricity portion of the unit,

 

students investigated series and parallel

_I II I I I'— Three cells wired in series
——i F— Single cell wired in a circuit
L Light bulb wired in a circuit
—W—— Resistor wired in a circuit

—-/— Switch wired in a circuit
both series and parallel circuit diagrams using II

circuits, making measurements and
observations in order to determine the
properties of current electricity for both types
of circuits. Students were expected to draw

Two cells wired in parallel
the standard symbols shown in Figure 2. Using

_.(: >._ Amm t
Ohm’s law, students were given values for 6 er

__®_ Voltrneter

Figure 2: Circuit diagram symbols

 

 

various parts within a circuit and would then

 

have to calculate the unknown value. It would

 

be expected that students be able to wire

 

_L_L

circuits on the circuit boards from a circuit

diagram, as shown in Figure 3. Once wired, l I

 

 

the current and voltage would be measured.

The observed difference in the brightness of

 
 

the light bulbs would offer students a visual

  

relationship between current, voltage and ‘— ‘—
resistance. Students would have the III
opportunity to observe properties associated Battery Holders T

 

 

 

Figure 3: Circuit diagram and drawn

with series and parallel circuits by wiring . , , ,
circuit on student circuit board

different circuit configurations on the circuit
boards. Each student would be expected to apply Ohm’s law to the circuits they had wired

on the circuit boards.

14

The magnetism and motor activities, found in appendix B, were modified from
activities in Electricity, Magnets, and Motors Teacher’s Guide (Cambridge Physics Outlet
1997). Students investigated the interaction between magnets and determining the
relationship between the poles of magnets and their magnetic fields through three different
investigations. The first investigation had students experimenting with magnets of different
sizes and strengths to determine the distance over which the two magnetic fields would
interact, either repelling or attracting each other. The second investigation measured the
distance of interaction between a magnet and other magnetic matter (pieces of metal
containing iron, nickel and cobalt). The final magnet investigation asks students to
determine whether shielding a magnet with a non-magnetic material has any influence on the
distance at which the magnetic field affects another magnet.

Most of the students previously had some experiences “playing” with magnets in
middle school science courses but were not familiar with how magnets interacted with wires
to induce electrical currents. Once students have an understanding of how magnets interact
they are asked to determine how magnets interact with electric currents to make an electric
motor work. Hands-on experimentation for students to learn how a motor works is provided
using the Cambridge Physics Outlet (CPO) Electric Motor <http://www.cpo.com>. Once
students have figured out how a motor works, they are then asked to apply what they have
learned in order to build and test motors with different magnet configurations. Use of a
photogate timer provides precise time measurements allowing students to calculate the
rotation speed and compare individual motor designs.

A Genecon hand-held generator clearly demonstrates the relationship between motors
and generators as the same piece of equipment can act as both a motor and a generator.

Students witness that electric motors and electric generators are based on the principle of

15

induction. By turning the handle of the generator students observe an electrical current being
generated as the lights on the circuit board light up. This provided students an opportunity
to see their motion, as mechanical energy, being converted to electrical energy. Magnetic
induction is also investigated through electrical transformers. Students observe several
different transformers in order to relate the number of turns of wire wrapped on the primary
and secondary coils of the transformer. Students are expected to calculate the ratio of turns
of wire and the resulting voltage for different examples of step-up and step-down
transformers.
Summary of Activities

The activities and assignments listed in Appendices B are cataloged in the order they
were assigned. The 17 different activities were designed so that students construct their
knowledge and experience the concepts relating electricity and magnetism. The book
Targeting Students’ Science Misconceptions (Stepans, J. 1996) was helpful in designing
some of the hands-on activities to either dispel previous misconceptions or help students
avoid the development of misconceptions by allowing them to hypothesize and test their
ideas as they began learning about current electricity.

The introduction to current electricity and circuits began with Activity 1: Creating
a Circuit. Students work in their groups to discover a variety of different ways to illuminate
a light bulb given one battery, two pennies, one light bulb and a wire. Afier discussing what
students determined about conductors and circuits from finding ways to light their light bulb,
two questions were posed to them: 1: How does a light bulb work? 2: How is a light bulb
considered a circuit? Each group was given a full sized light bulb to be “dissected” so the
internal parts that carry a current could be viewed. Current was demonstrated using a

conductivity indicator. The light bulb shines brighter as more salt is added to the water

16

creating a more concentrated electrolytic solution that conducts a current across the
electrodes. After the demonstrations, classes were divided into groups, given lists of terms
and phases relating to current electricity. Groups were asked to discuss definitions of each
term and to recall examples of two different circumstances observed throughout class
activities and demonstrations that exemplify each situation. Each group then shared their
responses with the entire class.

Activities 2, 3 and 4: These activities laid the basic groundwork for drawing, wiring,
and testing circuits and student activities centered on the discovery of series circuit
properties. Students used bulbs, wires, switches and batteries in drawing diagrams and wiring
circuits on the circuit boards. Two days were devoted to drawing, wiring, and testing series
circuits before beginning parallel circuits. Once students had a good foundation regarding
series circuits, and circuits in general, activities 5 and 6 introduced parallel circuits. Students
worked several days drawing and wiring parallel circuits and completing the parallel circuit
activities. As a freshman level course, the students were applying Ohm’s law only within
the individual series portions of the parallel circuits. The combination of drawing each
circuit diagram and then planning out where each wire would be attached gave students a
visual image of their circuit would look like. The benefit of planning and seeing where the
connections were to be made was evident (I-Iyerle, D. 1996).

The light bulb was used as an example of a circuit and how insulators and conductors
must be separated in order to maintain a constant current of electricity. In activity 7:
Resistance, students were exposed to different physical properties of wire that affect the
Wire’s resistance. The students wired circuits using five different spools of wire mounted
on a board. The length and gauge of wire varied and one spool of wire was made of material

other than copper, giving students a situation to examine varying degrees of resistance.

17

Several magnet activities gave students a quantitative look at magnets interacting.
Students measured the distance over which magnetic fields interact with other magnets and
also with magnetic substances. Observing how magnets interact with an invisible magnetic
field between the magnets and magnetic substances, showed students that magnets apply
forces and that force strength relates to measurable distances of attraction or repulsion. In
activity eight, students were able to observe magnetic fields by using compasses, iron filings
and paper clips. In activity 13, the students applied current around an iron nail to develop
and test electromagnets. Through experimentation, students determined the relationship
between the strength of an electromagnet and both the amount of current and number of
times the wire was coiled around the iron nail.

In activities 14 and 15, hands-on experimentation using the CPO Electric Motor
offered students the opportunity to observe the interaction of permanent magnets and
electromagnets to determine how a motor works. By realigning the magnets, students then
developed different motor configurations that were tested using a photogate and timer to
determine the speed at which the different motors rotated and the reliability of the motor to
start rotating under its own interacting forces.

The common use of transformers was introduced using the Internet and the article:
“Inside a Power-Cube Transformer” from How Stuff Works located at:
http://www.howstuffworks.com/inside-transformer.htm. Students looked inside a
transformer and were able to read a description of how they work. The activity that followed
had the students observing three different transformers that have been disassembled in order
to show the windings of wire. From their observations and reading, students are asked to
identify the type of transformer by looking at the windings along with the incoming and

outgoing wires. Students were also responsible for correlating the known ratio of voltage

18

or turns of wire in order to calculate an unknown quantity of voltage or turns of wire within

a coil.

19

Evaluation

Overview from Teacher Journal Entries

I found keeping a journal to be very helpful and rewarding. It was a new experience
for me and I definitely gained a greater insight into my own teaching and the interactions
with students. Recording my comments and observations, it was common to find myself
returning to student groups the next day to follow up with help or questions about the topics
that their group had either struggled with the day before or not yet completed. I felt much
more aware of student questions and misconceptions due to rereading my journal entries each
day. This unit started off unlike most other units; the students began raising questions
about electricity and magnetism as the objective list was handed out. Several students in
each hour made sirrrilar remarks about “wondering what made a motor go ‘round.” I
wheeled out a cart with a Van de Graaff generator on it and prepared to begin my
introductory demonstration and discussion of static electricity. As soon as students saw the
Van de Graaff generator they began asking “is that the “thing” that makes your hair stand
up.” Students were very attentive as I turned on the Van de Graaff generator and turned out
the lights so they could get a better view of the spark jumping from the dome to the discharge
rod. The room soon filled with oohs, aahs and wows! Placing the ribbon plume on the dome
of the generator produced many questions as the ribbons began to separate and float
effortlessly upward away from the dome and one another. Students were asked then to think
about what they had just observed and discuss their observations within their groups.

While students continued their discussions, a box containing a foil leaf electroscope,
a friction rod, two Styrofoam cups and a piece of fur was placed at their table. Right away
the questions began: “What are these for?” “Is this real animal fur?” “What are we going to

do with this stuff?” Then came the best lead in you could ask for, student “lAB6”remarked:

20

“I thought we were going to be learning about electricity, what do these things have to do
with electricity?” Students were asked to rub the friction rod with the fur and then to move
the rod near to the electroscope without touching the metal knob at the top. At this point the
reality that it had been raining all morning sunk in. This being the first hour of the day, the
humidity was so high that there was minimal reaction between the electroscope and the
fiiction rod. Students tried rubbing the firr on a Styrofoam cup and moving the “charged”
cup slowly toward the second cup that had been placed upside down on the table. NO
REACTION! The students were intrigued enough to ask what theyiwere supposed to be
observing. Since the activity was not cooperating, an explanation would have to do. Objects
can become charged by picking up or giving up electrons. An object that has picked up
electrons will have a negative charge. Given enough time, particles in the air, specifically
water molecules, will pick up the electrons from the surface of an object leaving it neutrally
charged. This would explain why when it is humid (moist) we have less trouble with static
electricity or static shock. There are more water molecules in the air to quickly pick up the
electrons and neutralize the charge (W irt, S. 2002). By the beginning of third hour class,
the sun was out, the humidity had decreased and the activities worked fine for the other two
classes that day. The first hour class was able to successfully complete and observe the
activity the following day.

The introduction to current electricity and circuits began with an activity asking
students to figure out different ways to illuminate a light bulb given one battery, two pennies,
one light bulb and a wire. Observing groups in each of the three classes, I saw a variety of
attempts and a lack of desire to try numerous configurations. As the students shared their
discoveries, it was evident that they were comprehending the difference between conductors

and insulators as they related to the parts of the light bulb and the positioning required to

.21

light them.

The discussion quickly shifted to the light bulb parts and how those parts interact to
convert electrical energy to radiant energy. The resistance of the filament seemed evident
as I lowered the electrodes into a beaker of distilled water and began to slowly pour in a
solution of salt water. The students were asked to discuss how or why the light given off by
the bulb changed as I poured more salt solution into the beaker. I was pleased with their
responses as they replied using terms such as conductivity, current, flow of current,
resistance. All three class periods were divided into groups and asked to define each term
on their list, then describe an example or two that they had observed during class activities.

The focus then shifted to address circuits. Students would be drawing circuits, wiring
circuits, and discovering the properties of circuits. It became clear that students were
interested in the activities they were working on and many times I observed students express
such joy when the circuits they had wired illuminated the bulb. I believe it was the instant
feedback that brought about this reaction. As soon as students completed each circuit they
could throw the switch and see immediate results. Several groups took some coaxing to work
with their wires and solve the problem when the light did not light up. I was constantly
asking them to determine: “Is it the bulb?” “Is it the batteries?” Have you checked all your
connections?” As I circulated between groups during the beginning activities, it became
apparent that many students were not correlating what we had defined as a series circuit and
the circuit diagram they had drawn. I frequently saw multiple wires coming out of the same
clip on the circuit board and had to remind them of the reason I had them first drawing the
diagram of the circuit then referring to their diagram, they were to draw the. wiring on the
picture of the circuit board before beginning to actually wire the circuit board. After pointing

out my reasoning the several students “had the light go on!” Student lPSlB commented,

22

“Now that makes sense to me! The definition actually tells you how to draw the circuit and
the circuit diagram shows how to attach the wires when you do the circuit.” In another class
the same day student 19P3 remarked, “This is much easier when you use all the parts to end
up with a circuit that actually wor .”

As the students progressed to wiring parallel circuits, it became clear that it was not
always as simple to wire a parallel circuit as it was to draw a parallel circuit. In activity 4
it was again made evident that students were more successful wiring their circuits if they had
first drawn the diagram and then drew in where they would attach their wires on the picture.
As I observed groups working, I constantly had to rerrrind them to look at the diagrams they
drew and transfer the circuits to the picture and circuit board.

Several times I heard comments such as: “Now I see”, “I figured there had to be some
way for each part to act on its own”, and “That makes sense why there’s more than one
switch in each room.” The most frequent journal entry was, “They got it!” I also wrote: “The
circuit boards have worked great, they have allowed students to construct various circuits
with much less hassle and frustration then previous labs using loose parts.”

As each of the classes started into the magnetism section of the unit, I allowed them
some “experience” time with the magnets. This gave me a perspective on what they already
knew about magnets before starting the activity. I was surprised at how few students had an
idea of how a magnetic compass worked. Working with compasses gave me an opportunity
to interact with small groups and give some students more individualized attention in order
to help them comprehend the interactions they were observing between magnets and their
magnetic fields. As noted in my journal: “Magnets intrigue the students.” “They are
fascinated by what they can’t see yet they observe that there is something there around each

magnet.” “Many of these students could play with these magnets for hours at a time and

23

never get bored with them.”

I was very pleased with the activities involving the CPO Electric Motor. Student
6PSO3 made the comment, “I liked getting to work with the motors, they REALLY helped
me to understand how they work. It was a lot of fun.” Student 1106P stated, “Building the
motor was a very good way to see and learn what is going on inside of a motor. I never had
any idea that it was actually so simple.” “Using the CPO Motor made it much easier to
understand what I was looking at when I took apart the motors in my remote-controlled car”
remarked student 1780].

Most of the students were unfamiliar with the function of transformers even though
most of them used a transformer repeatedly with their CD player. Student 12PSO6 remarked,
“I often wondered how my CD player could work with just two little batteries and also use

’96

regular electricity. ‘This makes sense to me now that I understand how electricity can make
an electromagnet. The word transformer describes what it does, it transforms the push on
the current so the electricity can be used for different things.” said student O8P3. It was
obvious when discussing transformers that students were farrriliar with the term but never
had a concept of what a transformed did. With the use of small battery powered appliances,
like CD players, becoming more and more common, students were aware of transformers
being used but without knowing what they actually were or “how” they worked. The
example of the CD player was the model which most students were able to identify.

Other than the few students that had made a conscious decision not to participate in
the activities, students enjoyed the unit and seemed to have learned what was expected of
them. There were three students in my third hour class that did not take an active part to

actually learn as they were attempting the activities and seldom completed an activity or

assignment during this and previous units. These students chose failure rather than making

24

any attempt to discover and learn what is expected in the class.
Qualitative Data

I would consider the student achievement to be satisfactory over the course of the
electricity and magnetism unit. Students were asked to complete a final survey, Appendix
B-26, after the unit was completed, students overwhelmingly wrote positive comments
relating they had a significant increase in their understanding of the topics covered. Student
16P01 made the statement: “I didn’t know anything about electricity when we started, but
I now feel that I have a good understanding of it and look forward to taking Physics and
learning more.” “When I first read through the objectives, I thought this was going to be a
real tough unit. But as we started into the labs I thought it was very easy to learn this stuff
because of all the examples and hands-on activities” stated student 22803. “I learned a lot
about electrical currents which I thought was very interesting”was noted by student 3P23.
Student 6SP3 wrote the following comments “the labs that we did with the motors helped
me a lot, I never knew that motors were so simple. It was a big help to be able to make
different motors and test them so that we could see the differences. Without the motor
activities I don’t think that I would have understood them.” 15 SP3 wrote “I knew most of
the stuff about magnets and magnetic fields but I never knew magnets were used in motors
and generators and so important.”

Question number five on the student survey ask students to offer input that would
help me improve the electricity and magnetism unit. More than two thirds of the surveys
had comments stating that I should continue using hands-on activities and that the students
feel they learn so much more and better by doing the activities.

Of the 61 students that completed the unit survey, 45 students, 74%, rated their

understanding of electricity and magnetism at a five or six on a scale from one to six, with

25

one being no understanding and five and six a good understanding.
Quantitative Data

The final student evaluation for the electricity and magnetism unit was a 39-question
multiple choice test, found in appendix B. The test consisted of 14 questions related to
objective 1 information, 10 questions for objective 2 and 15 questions that pertained to
objective 3. The test scores were very close from one class period to another as shown in

Table 3' Table 3: Average Test Score and Percent Listed

       
   

32 / 39 29.4 / 39
82% 75%

31.4/39 '.
81%

 

 
 

 

Girls Boys Girls Boys Girls Boys

31/39 33.6/39 292/39 297/39 269/39

80% 86% 75% 76% 69%
“

 

 

 

 

7%

   

 

 

 

 

The scores were also broken down into categories of boys and girls. The third hour
class period showed very little difference in scores between girls and boys unlike the other
two class periods. Sixth hour showed a dramatic range difference between the girls and the
boys. I would attribute that difference to the fact that the boys in sixth hour were very
involved in the activities and interested in learning about electricity and magnetism. The
majority of the girls in the same class tended to be very passive when it came to taking an
active part during the investigations. From previous discussions with their parents and other
teachers, these girls had a reputation for their lack of motivation in all their classes.

Since I have been teaching the same subject over the past three years, I feel that I can
justifiably state that the hands-on lessons and activities were the main factor in improving

the understanding of electricity and magnetism by this study group. The activities were more

26

effective in engaging the students and helping them to gain an understanding of electricity
and magnetism as outlined in the objectives. From my observations, the Physical Science
class of 2001 was much more motivated and had a higher caliber acaderrric record in most
of their courses than did this years class. Yet this year’s students scored 3.6% higher on the
unit test than last year’s students. Scores for the same unit compared to student scores from
two years previous were 5.5% higher for the study group, as shown in Table 4 and Figure

4.

Table 4: Electricity and Magnetism Unit Test Scores
for Physical Science classes in 2000 to 2002

I 2000 | 2001 | 2002

I 73.0% I 74.9% I

 

 

  
 

78.5% I

 

 

 

27

The test scores were consistent from one class period to another for all three of the
objectives, ranging from a low of 77% for objective 3 and a high of 82% for objective 2.
Figure 5 shows a comparison between each of the objective scores and the overall percentage
for each class. The third hour class was had the lowest scores for two of the three objectives
and the lowest average test score for the three classes. This has not been the trend since the
class as a whole had out performed the other two classes throughout most of the semester.
From my observations, the main reason for the lower third hour scores was due to an
apathetic attitude as the end of the school year we got closer. I frequently found more

students in third hour off task and inattentive than in the other two classes.

Test Results: Percent Total Score and Objectives

—L
o
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A
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9.24.1.4“. 4— 4—

 

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O

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

20
0 u.-
Total Score Obj. #1 Obj. #2 Obj. #3
[I] First Hour a Third Hour
Z Sixth Hour I Average Score

Figure 4: Bar graph showing the total score for each hour
and the average score on each objective on the
Electricity and Magnetism Test

28

Each test question was evaluated to determine how frequently each question had
incorrect responses. The 14 questions relating to objective 1: The student will be able to
define electricity, in terms of circuits, and discuss the relationship among voltage, current,
and resistance within different circuits and calculating values within a circuit using Ohm’s
law, are shown in Figure 5. Four of the questions had less than 75% of the students choosing
the correct answer. Three of these four questions, numbers 2, 12 and 13, required students
to calculate the amount of current flowing in a circuit. There were two different circuit
diagrams that apply to the three questions, one of them showing three batteries wired in
series and the other with three batteries wired in parallel. Before the students could calculate
the current, they had to correctly apply the concept of voltage to batteries wired in parallel
and in series. Students also had to determine which path the current would flow through and
then calculate the total resistance within that path and applying Ohm’s law to determine the
value for the current that would flow through that part of the circuit. This type of multi-step

problem has several possibilities for mistakes that would result in incorrect answers.

Percentage correct for objective 1 questions

 

#l #2 #3 #4 #5 #6 #7 #8 #9 #10 #ll #12 #l3 #14

Figure 5: Bar graph showing the percentage of students scoring correct
responses on objective 1 questions.

 

 

29

Questions from objective 2: The student will be able to identify parts within an
electrical circuit, diagram and construct circuits, and identify properties associated with
series and parallel circuits, averaging 82% correct responses, the highest scoring objective
on the unit test. As shown in Figure 7, there were 10 questions relating the information for
objective 2, with only one question having below 79% correct responses. Question number
18 was answered correctly by only 55% of the students. The question asked them to identify
the total voltage of the cells in a circuit. The circuit was pictured having three parallel cells
with quantitative information listed below the figure, each cell is rated at 1.5 volts. This
question tested the student’s knowledge of voltage adding when cells are wired in series but
not adding when wired in parallel. Of those students that answered question 18 incorrectly,
23 of the students, or 37% had added the voltage for the three cells and given that as their
answer. The knowledge application of this question relates directly to two of the questions
students scored low on for objective 1 since the same circuit diagram was used for those two
questions. The property difference between series and parallel circuits was consistently
reinforced

Percentage correct for objective 2 questions
throughout the 100 .i

60:
I
20

0A ‘,

#15 #16 #17 #18 #19 #20 #21 #22 #23 #24

Figure 6: Bar graph showing the percentage of students
scoring correct responses objective 2 questions.

 

class activities.

     

30

Of the last 14 questions pertaining to objective 3: The student will be able to describe
how magnetism, magnetic fields and magnetic poles interact and how they relate to motors,
generators, and transformers, only two questions had less than 70% correct responses. For
questions 28 and 29, students scored correctly 60% and 68% respectively. I’m not certain
there is an explanation as to why question 28 was marked incorrect more fiequently than
question 26 since they were basically questions of an opposite nature. Question 28 asks the
student to identify the type of transformer that would be found outside their home and
question 26 relates the type of transformer that would increase AC voltage as it leaves an
electrical power plant. Question 29 is a straightforward question about the energy conversion

that occurs in a motor. Energy and energy conversions were also covered in a previous unit.

Percentage correct for objective 3 questions
100

 

 

 

#25 #26 #27 #28 #29 #30 #31 #32 #33 #34 #35 #36 #37 #38 #39

Figure 7: Bar graph showing the percentage of students
scoring correct responses objective 3 questions.

31

Discussion

The goal of this new unit was to implement an electricity and magnetism unit with
more engaging lessons and activities that would enhance the learning environment in my
Physical Science classroom. After looking over the test data and reading through the journal
I kept, it appears to me the goal has been met. From everyday observations it was obvious
to me that students were actively involved in the learning process through meaningful
activities that raised good interactive questions from the students. I was told by students
repeatedly that the class period went by so quickly due to “doing” things instead of just
sitting through lectures or doing book work. One remark written on the student surveys
stood out from all the others and made the student’s point very clear. “Thank you for making
this a hands-on class. The stuff about electricity and magnetism seemed so easy to learn
because of all the things that we did to help us learn. I thought the activities were fun and
interesting and I can’t imagine having to learn fi'om just reading a book or having a teacher
lecture. This was my favorite class and it always seems to go so fast because we are doing
things and not just sitting there. Thanks again.”wrote student 22PS3. Student 01 SP1 I wrote
“Doing the hands-on stuff is so much better than using the book.” After reading comments
like these, I was sure it had been worth the effort I put into changing how this unit was
taught.

I clearly observed a situation where the diversity of educational background had less
to do with a student’s success than did the interest and motivation to be actively involved and
making attempts to discover answers. Autonomy, involvement and the activities had a
positive impact on student interest throughout this unit, allowing students to work with more

independence to discover answers to the questions that were posed to them. During the

32

teaching of this unit I have seen how active involvement and hands-on manipulation by
students allows teachers to give them greater responsibility, in their role as a student, to
become educated and gain understanding of concepts necessary to be considered
scientifically literate. The interaction with lab equipment and cooperation among students
during group activities offers each student an opportunity to employ their own personal
strengths and learning styles in order to learn successfully. It is likely that this approach will
not work for all students, but has increased the participation and understanding for most
students I have observed. It takes a certain amount of training and/or conditioning to develop
feelings of confidence and comfort so students will ask questions (form hypotheses) that can
be tested through experimentation in order for them to arrive at meaningful conclusions and
comprehend the essential concepts and skills.

Reflecting on the preparation and teaching of this unit, I feel it has refreshed my
teaching and given me a clearer vision of the direction I want to go with my teaching. I will
to continue to use the multiple intelligence and brain research data to enhance the hands-on
active approach to educating students in the areas of Physical Science. I plan to make
improvements in the activities that address generators and transformers and add some new
activities relating to capacitors. The purchase of some additional equipment would require
fewer students per group so that more students have the opportunity to interact and discover
information for themselves. Too often students get caught up in letting others “do” the
activity and then they seem to lose interest. The more exposure each student has to interact
to quality, hands-on, engaging activities the greater their chance of learning. I look forward
to continuing to expand and improve this unit by making changes and additions that will

facilitate the development, interest and understanding of electricity and magnetism.

33

APPENDICES

Appendices A: Learning Styles Information

34

A 1 Multiple Intelligence: Seven Styles of Learning
Linguistic Learner
- Tends to like to: read, write, and tell stories.
0 Tends to be good at: memorizing names, places, dates, and trivia.
0 Tends to learn best by: saying, hearing, and seeing words.

Logical/Mathematical Learner
- Tends to like to: do experiments, figure things out, work with numbers,
ask questions, and explore patterns and relationships.
0 Tends to be good at: math, reasoning, logic, and problem solving.
- Tends to learn best by: categorizing, classifying and working with abstract
pattems/ relationships.

Spatial Learner
- Tends to like to: draw, build, design and create things, daydream, look at
pictures/slides, watch movies and play with machines.
- Tends to be good at: imagining things, sensing changes, mazes/puzzles,
reading maps & charts.
- Tends to learn best by: visualizing, dreaming, using the mind’s eye and
working with colors/pictures.

Bodily/Kinesthetic Learner
0 Tends to like to: move around, touch, and talk and use body language.
0 Tends to be good at: physical activities (sports/dance/acting), and crafts.
0 Tends to learn best by: touching, moving, interacting with space and processing
knowledge through bodily sensations.

Musical Learner
0 Tends to like to: sing, hum tunes, listen to music, play an instrument,
and respond to music.
0 Tends to be good at: picking up sounds, remembering melodies, noticing
pitches/rhythms, and keeping time.
0 Tends to learn best by: rhythm, melody, and music.

Interpersonal Learner
0 Tends to like to: have lots of friends, talk to people, and join groups.
0 Tends to be good at: understanding people, leading others, organizing,
communicating, manipulating, and mediating conflicts.
0 Tends to learn best by: sharing, comparing, relating, cooperating, interviewing.

Intrapersonal Learner
0 Tends to like to: work alone and pursue own interests.
0 Tends to be good at: understanding self, focusing inward on feelings/dreams,
following instincts, pursuing interests/ goals, and being original.
0 Tends to learn best by: working alone, individualized projects, self-paced
instruction, and having own space.

35

A 2 Multiple Intelligence Evaluation Questions:

WHAT KIND OF LEARNER M. 1.?

1. I can hear words in my head before I read, speak, or write them down.

N

. I can easily compute or calculate numbers in my head.

3. I often see clear visual images when I close my eyes.

A

{It

. My best ideas often come to me when I’m out for a long walk or a jog or when

I’m busy doing some other kind of physical activity.

. I can tell when a musical note is off key.

6. I am the sort of person that people come to for advice at my job or here in school.

\1

00

\O

10.

11.

12.

13.

14.

15.

l6.

17.

18.

19.

. I regularly spend time alone meditating, reflecting, or thinking about important questions.
. I show an ability for word games like Scrabble, Anagrams, or Password.

. I enjoy playing games or solving brain teasers that require logical thinking.

I enjoy doing jigsaw puzzles, mazes, and other visual puzzles.
I need to touch things in order to learn more about them.
My life would be poorer if there were no music in it.

When I have a problem, I’m more likely to seek out another person to help me
rather than work it out on my own.

I have opinions that set me apart from the crowd.

English, social studies, and history are easier for me in school than math and science.
My mind searches for patterns, regularities, or logical sequences in things.

I have clear, vivid dreams at night.

I frequently use hand gestures and body language when talking with someone.

I sometimes find myself walking along with a television jingle or other tune
running through my mind.

36

20.

21.

22.

23.

24.

25.

26.

27.

28.

29.

30.

31.

32.

33.

34.

35.

I consider myself a leader (or others have called me a leader).

I have some important goals for my life that I think about on a regular basis.

My conversation includes frequent references to things that I’ve read or heard about.
I believe that ahnost everything has a rational explanation.

I can generally find my way around unfamiliar territory.

I would describe myself as coordinated.

I often make tapping sounds or sing little melodies while working, studying,
or leaning something new.

I feel comfortable in the midst of a crowd.
I consider myself to be strong willed or independent minded.

I’ve written something recently that I was very proud of or that earned rne
recognition fiom others.

I sometimes think in clear, abstract, wordless, image less concepts.
Geometry is easier for me than algebra in school.

I need to practice a new skill rather than simply reading about it or seeing a video
that describes it.

If I hear a musical piece once or twice, I am usually able to sing it back fairly accurately.

I like to get involved in social activities connected with my school,
church, or community.

I keep a personal diary or journal to record the events of my inner life.

37

Circle the number for each statement that describes you.

A 3 The Multiple Intelligence Inventory

WHAT KIND OF LEARNER M. 1.?

Student Score Sheet

 

 

 

 

 

1 2 3 4 5 6 7

8 9 10 1 1 12 13 14
15 16 17 18 19 20 21
22 23 24 25 26 27 28
‘ 29 30 31 32 33 34 35

 

 

 

 

 

 

 

 

 

Afier you have responded to all of the statements, add up the number of items you circled
in each column. The number of items you circled in each column represents your score
for that learning style. The columns match up with the seven learning styles listed below.

1. Linguistic

3. Spatial

5. Musical

7. Intrapersonal

2. Math/Logical

4. Bodily/Kinesthetic

6. Interpersonal

38

 

A 4 The Multiple Intelligence: Classroom Strategies
The Multiple Intelligences: Checklist for Teachers Regarding Lesson Balance
Consider the following descriptors.

Logical/Mathematical Visual/Spatial Intrapersonal
0 problem solving 0 charts 0 individual study
0 tangrams O graphs 0 goal setting
0 coding 0 photography 0 individual projects
0 geometry 0 visual awareness O journal log keeping
O measuring 0 organizers 0 personal response
0 classifying 0 visual metaphors 0 personal choice
0 predicting 0 visual analogies 0 individual reading

0 logic games
0 data collecting

0 playing instruments

0 visual puzzles
0 3D experiences

0 nonfiction reading

0 self-esteem activities

0 serialing 0 painting
0 attributes O illustrations Interpersonal
O experimenting 0 story maps
0 puzzles O visualizing 0 learning groups
0 manipulatives O sketching 0 sharing
0 scientific model 0 patterning 0 group work
0 money 0 mind maps 0 peer teaching
0 time 0 color 0 social awareness
O sequencing 0 symbols 0 conflict mediation
0 critical thinking 0 discussion
0 peer editing
Musical/Rhythmic Verbal/Linguistic 0 cross age tutoring
0 social gathering
O singing 0 stories 0 study group
O humming O retelling 0 clubs
0 rhythms O journals 0 brainstorming
O rap 0 process writing
0 background music I reader’s theater Bodily Kinesthetic
0 music appreciation 0 story telling
O mood music 0 choral speaking 0 drama
0 patterns 0 rehearsed reading 0 field trips
0 form 0 book making 0 activities
0 rhythm O speaking 0 creative movement

0 hands on experiments

0 research 0 body language

0 speeches 0 using manipulatives
O presentations 0 phys. ed. activities
0 listening 0 crafts

A 5 Multiple Intelligence Assessment Menu

39

A 5 Multiple Intelligence Assessment Menu

Verbal-Linguistic
Intelligence
(Language Arts-Based
Assessment Instruments)

0 written essays

l vocabulary quizzes

O recall of verbal information
0 audio cassette recordings

0 poetry writing

0 linguistic humor

0 formal speech

0 cognitive debates

O listening and reporting

0 learning logs and journals

Musical-Rhythmic
Intelligence

(Auditory-Based
Assessment Instruments)

0 creating concept songs

0 illustrating with sound

0 discerning rhythmic patterns
0 composing music

0 poetry writing

0 linguistic humor

0 formal speech

0 cognitive debates

O listening and reporting

Logical-Mathematical

Intelligence
(Cognitive Patterns - Based
Assessment Instruments)

0 cognitive organizers

O higher-order reasoning

0 pattern games

0 outlining

O logic & rationality exercises
0 mental menus and formulas
O deductive reasoning

O inductive reasoning

I calculation processes

0 logical analysis and critique

Interpersonal

Intelligence
(Relational - Based
Assessment Instruments)

0 cognitive organizers

O higher-order reasoning

0 pattern games

0 outlining

0 logic & rationality exercises
0 mental menus and formulas
O deductive reasoning

O inductive reasoning

O calculation processes

40

Visual-Spatial
Intelligence

(Imaginal-Based

Assessment Instruments)

0 murals and montages

O graphs and illustrations

0 visualization & irmgination
0 read, understand, create Imps
O flowcharts and graphs

0 sculpting and building

0 imaginary conversations

0 mind mapping

0 video recording, photography

0 manipulative demonstration

Intrapersonal

Intelligence
(Psychological-Based
Assessment Instruments)

0 murals and montages

o graphs and illustrations

0 visualization & imagination
0 read, understand, create maps
0 flowcharts and graphs

0 sculpting and building

0 imaginary conversations

O mind mapping

0 video recording, photography

APPENDICES

Appendices B: Electricity and Magnetism Unit Student Work

41

Physical Science: Physics Hour Number—
Electricity Name
Bl Activity 1: Creating a Circuit Date

 

 

What is current electricity?
Current electricity is electrons in motion. Electricity is a kind of energy. Electricity can
be sent through a system or path of wires that are commonly called a circuit. The
electrons must be able to flow in order to complete a circuit.

Use problem solving! Use only the materials specified!
Draw a clear, simple sketch of each solution.

1.) Using only 1 dry cell, 1 wire and 2 pennies:
Make the wire warm without touching the wire directly to the dry cell.
(Disconnect as soon as you feel heat to save your dry cell from an energy-
draining short circuit).
5mm

What does this tell you about the pennies?

 

2.) Using only 1 dry cell and 1 wire and 1 bulb:
Make the lightbulb light up. Sketch
Avoid connections that make the wire warm.
The bulb will never light in a short circuit.

3. Using only 1 dry cell and 1 wire and 1 bulb:
Make the bulb light up in as many different ways as you can.
Make a sketch of the different ways that you can light the bulb.
(Hint: There are 4 different ways.)
Sketches

42

4. Using only 1 dry cell and 1 wire and 1 bulb and 1 penny: Sketch
Light the bulb without touching the bulb to the dry cell.

5. Light up the bulb using 2 dry cells and 1 wire and 1 bulb. Sketch

How would you compare the difference you see using a single dry cell versus 2 dry cells?

 

6. Draw lines matching the parts with the correct position of identification on
the bulb picture. Trace the path current flows through to light the bulb.

Ceramic Insulation Material
End Metal Contact Point
Filament Wire - Tungsten
Glass envelope - Bulb
Glass Support Mount
Screw Threaded Metal Base
Solder Dot

 

Support Wires
«1.1"; .mrtnhrh.

-' Ill-11111111 .

 
 
 

Vacuum or Inert Gas

   

. murmur

43

Physical Science: Physics Hour Number_
Electricity Name
B2 Activity 2: Drawing a Circuit Date

 

 

1. Define a circuit:

 

2. Define a series circuit:

 

3. Define a parallel circuit:

 

Neatly draw each of the parts that will be used in drawing circuit diagrams.

Wire: Li ghtbulb: Resistor:
Switch: Battery (Cells): Three series cells:
Ammeter: Voltmeter: Three series bulbs:

Draw 2 bulbs, 1 switch and 2 cells in a series.

Diagram each circuit in the boxes below.

 

 

 

 

A. Draw 3 cells, 2 bulbs, 1 switch, and B. Draw 1 cell, 4 bulbs, 1 switch,

2 bulbs, and one resistor in series. 2 resistors, l ammeter, 2 bulbs in series.
C. Draw 4 cells, 3 bulbs, 1 switch, D. Draw 3 cells, 3 bulbs, l resistor,

2 bulbs and 1 switch in series. 2 bulbs and 1 switch in series.
E. Draw 2 cells, 1 bulb, 1 ammeter, F. Draw 1 cell, 2 bulbs, 1 ammeter,
1 switch, 2 bulbs, and 1 resistor in 2 bulbs, and l resistor in series.
series.

 

 

45

 

Physical Science: Physics Hour Number_
Electricity Name
B 3 Activity 3: Circuits - Date

Relating Voltage & Current
1. Look at one of your batteries (cells), what is the voltage printed on the cell?

 

 

Measure the voltage of each cell.
Does the measurement match the voltage printed on the cell?

 

2. If you wire two cells in series,
how much voltage will you have? Voltage of three cells?

3. If you wire two cells in parallel,
how much voltage will you have? Voltage of three cells?

4. Some bulbs in your kit are given a rating of 1.3 volts,0.3 amps.
Measure the current through each bulb and then calculate the resistance of the light
bulbs. Givens Formula Calculation

Bulb Resistance =
5. There are also some bulbs that are rate at 3.8 volts, 0.3 amps.

Measure the current through each bulb and then calculate the resistance of the light
bulbs. Givens Formula Calculation

Bulb Resistance =
6. Measure each cell’s voltage and the resistance of each bulb above then calculate the
current that will flow through each circuit in the situations below.

A. One cell and one bulb from #4:

Givens Formula Calculation
Current =
B. Two cells and one bulb from #4: ‘
Givens Formula Calculation
Current =
C. One cell and one bulb from #5:
Givens Formula Calculation
Current =
D. Two cells and one bulb from #5:
Givens Formula Calculation
Current =

46

Draw the circuits described below in the order they are given.
Show your circuit drawings to Mr. Dean to have them checked.
When your drawings have been checked, you are to wire each circuit a circuit board.
MAKE NEAT, CLEAR DRAWINGS USING CORRECT SYMBOLS!

 

 

Circuit A: Circuit B:

A series circuit consisting of 1 cell, A series circuit consisting of 1 cell,
1 switch and l bulb. 1 switch, 1 bulb and lswitch.
Checked: Checked:

Circuit C: Circuit D:
A series circuit consisting of 2 cells, A series circuit consisting of 2 cells,
1 switch, 1 bulb and 1 switch. lswitch, 2 bulbs and 1 switch.
Checked: Checked:

 

 

 

 

1. Could you observe a difference in the brightness of the bulbs in the four circuits?

Explain your observation:

 

 

2. Rank the circuits in order of the brightness of the bulbs.
Circuit A: Circuit B:

Circuit C: Circuit D:

47

Physical Science: Physics
Unit: Electricity

B4 Homework #1 Drawing Series Circuits

Hour Number
Name
Date

 

 

Ohm’s law Formulas: I = V -=- R
Diagram each circuit in the boxes below.
Use the proper symbols for each of the parts of the circuit.

 

 

Circuit A: Draw a series circuit with
3 cells, 4 bulbs, 1 switch, one resistor,
2 bulbs, 1 ammeter and 1 resistor.

Show the direction of flow in your
circuit.
What would the ammeter reading be in
this circuit when:

Each cell = 1.5 V

Each bulb = 2.8 ohms

Each resistor = 11 ohms
SEW your worlfl

Current =

 

 

Circuit B: Draw a series circuit with
3 cells, 3 bulbs, 1 switch, 3 bulbs,
2 resistors and 1 ammeter.

Show the direction of flow in your
circuit.
What would the ammeter reading be in
this circuit when:

Each cell = 1.3 V

Each bulb = 1.6 ohms

Each resistor = 5 ohms
Show your wcmgfl

Current =

 

 

48

 

Physical Science: Physics Hour Number
Electricity Name
B 5 Class Starter 1: Circuits & Ohm’s Law Date

 

 

1. What is current?

 

What is the symbol for current? What is the unit of current?

2. What is voltage?

 

What is the smbol for voltage? What is the unit of voltage?

3. What is resistance?

 

What is the symbol for resistance? What is the unit of resistance?

4. State Ohm’s law. How does it relate current, voltage, and resistance?

 

5. Identify which of the following items describes current, voltage, or resistance.
Write the symbol for each quantity on the line.
For current use I; for voltage use V; for resistance use R.

l. The quantity that is measured in amperes or commonly called amps.
2. Quantity that is measured in units of ohms.
3. The flow of charge past a certain point within a circuit.
__4. A property of wire that depends on the length and guage of a wire.
5. The rate at which charges pass a given point in a circuit.
6. A quantity that is measured with an ammeter.
_7. A property of wire that depends on the material that makes up the wire.

8. Describes a potential difference between two different positions.

 

9. Opposes the flow of electric charge.

10. Quantity that is measured in volts.

11. Property of wire depending to some extent on the temperature of wire.

12. Quantity that flows from positive to negative.

49

Physical Science: Physics Hour Number

 

 

Electricity Name
B 6 Activity 4: Series Circuits Date
- Ohm’s Law Cale.

Ohm’s law states that current (I) is proportional to voltage (V). That means that as current
increases voltage increases, they both increase or they both decrease. Resistance (R) is
related to current (I) in the opposite way. As current increases, resistance decreases, and
as resistance increases, current will decrease. Current is measured in amperes (A or amps),
voltage is measured in volts (V), and resistance is measured in ohms (0).

Apply Ohm’s law to the problems below.
Ohm’s law Formula: I = V + R
Power (in Watts) is equal to voltage times current. P = V x I
1. How many amps of current are supplied by a force of 12 volts through a wire that
has a resistance of 6 ohms? What power is produced?
Givens Formula Calculations
Current

 

Power
2. Double the voltage with the same wire, calculate this change in current and power.
Givens F orrnula Calculations
Current

 

 

Power
3. How many volts are required to force 4 amps of current through a wire
with a resistance of 5 ohms?
Givens Formula Calculations
Volts

 

 

Power
4. If you double the resistance in question 3, keeping the voltage constant,
how does this change the current and power?
Givens Formula Calculations
Current

 

 

Power

 

5. A light bulb draws 0.2 amps of current when it is connected to a source of 2 volts.
What is the resistance of the light bulb? What is the power produced?
Givens Formula Calculations

Resistance

Power

 

50

Drawing and Wiring Series Circuits

Circuit A: Draw a series circuit with 2 cells, 2 bulbs and 1 switch in a series.

 

 

 

 

 

 

 

 

 

 

 

Checked
0
é @ "Hfl
9
§ .
_L
Checked

 

51

Circuit B:
Draw a circuit with 3 cells, 2 bulbs, 1 switch, 1 bulb, 1 bulb, 1 ammeter in series.

 

 

 

 

 

 

 

 

 

 

Checked
[cl—- 4
T
m
Checked Ammeter Reading

 

 

52

Circuit C:
Draw a circuit with 2 cells in series, 1 switch, 2 bulbs and 1 ammeter in series.

 

 

 

 

 

 

 

 

 

 

Checked
[u H 0]
Fl“
_01
Checked Ammeter Reading

 

 

53

Physical Science: Physics Hour Number_
Electricity Name
B 7 Class Starter 2: The Light Bulb as a Circuit Date

 

 

1. Identify the locations of the following parts that make up the common light bulb.

Glass envelope - Bulb Screw Thread Metal Base
End Metal Contact Point Ceramic - Insulation Material
Filament Wire - Tungsten Glass Support - Mount
Vacuum or Inert Gas Solder Dot Support Wires

 

 

 

 

2. How or why is a light bulb considered a circuit?

 

 

 

3. What type of circuit is the light bulb, series or parallel? EXPLAIN !!

 

4. What keeps a light bulb from shorting out?

 

Why is that important?

 

 

54

Physical Science: Physics Hour Number_
Electricity Name
B 8 Activity 5: Drawing a Parallel Circuit Date

 

 

1. Define a circuit:

 

2. Define a parallel circuit:

 

3. Neatly draw each of the parts that will be used in drawing circuit diagrams.
// = parallel
Three parallel cells: Three parallel bulbs:

Two // cells // 1 bulb and 1 ammeter: Three // cells// 2 bulbs in series //
1 voltmeter:

Draw a neat diagram of each circuit below.
Circuit A. A circuit with 3 series cells // 1 switch, 1 resistor and 2 bulbs
// 1 switch, 3 bulbs and 1 switch // 2 bulbs, l resistor and 1 switch.

Number the circuits 1, 2 and 3 from left to right and answer the following questions.
All resistors are 6 ohms and all bulbs have a resistance of 0.2 ohms.

A. Ifall switches are closed,
which segment of the entire circuit would have the greatest resistance?

B. If all switches are closed,
which segment of the entire circuit would have the least resistance?

 

C. Which segment of the entire circuit would have the brightest bulbs?

 

55

Circuit B. A circuit with 3 // cells // 1 bulb, 1 switch, 1 bulb // 2 bulbs, 1 switch, 1
resistor

Number the circuits 1 and 2 from left to right and answer the following questions.
All resistors are 5 ohms and all bulbs have a resistance of 0.3 ohms.

A. If all switches are closed,
which segment of the entire circuit would have the greatest resistance?

B. Which segment of the entire circuit would have the brightest bulbs?

C. What segment do the switches have on the resistance in a circuit?

 

Circuit C. A circuit with 4 // cells // 4 bulbs and 1 switch // 1 switch and 3 bulbs
// 1 switch and 2 bulbs //1 switch and 1 bulb.

Number the circuits 1, 2, 3 and 4 from left to right and answer the following questions.
All bulbs have a resistance of 0.23 ohms.

A. If all switches are closed,
which segment of the entire circuit would have the greatest resistance?

B. If all switches are closed,
which segment of the entire circuit would have the least resistance?

 

C. Which segment of the entire circuit would have the brightest bulbs?

 

D. Which segment of the entire circuit would have the dimmest bulbs?

 

56

Physical Science: Physics
Electricity

B 9 Class Starter 3: Drawing Parallel Circuits Date

Hour Number_
Name

 

 

Diagram each circuit below then have each one checked by a different student.

 

A. 2 // cells // 1 bulb and 1 switch
// 1 bulb and 1 switch.

Person Checking:

 

B. 3 // cells // 2 bulbs // 1 switch,
1 resistor and 1 bulb // 1 switch and 3
bulbs.

Person Checking:

 

 

C. 2 //cells // 2 bulbs // 1 switch and
3 bulbs in series.

 

 

Person Checking:

 

D. 2 series cells in series // 1 switch
3 bulbs // 1 switch and 4 bulbs in series.

 

Person Checking:

 

57

 

Physical Science: Physics Hour Number_
Electricity Name
B 10 Activity 6: Draw & Wire Parallel Circuits Date

Drawing and Wiring Series Circuits
Draw each of the circuits described below as a rectangular circuit with the correct
symbols and then draw how you would wire the circuit. Have your pictures checked, then
wire each circuit on a circuit board.

 

 

 

Circuit 1: Circuit 2:
A circuit with 3 cells in series and 1 bulb. A circuit with 3 parallel cells and one
bulb.
Circuit 1: Circuit 2:

it? i nan i

Compare the brightness of the bulb in each for the two different ways you wired the same
parts. Explain why you see a difference in the brightness of the bulb.

 

 

 

 

 

 

 

Checked

58

Circuit A: Draw a circuit consisting 3 // cells // 2 bulbs // 2 bulbs and 1 switch.

 

 

 

 

Checked

 

I

 

 

[0H0]

 

 

Checked

59

Circuit B:

Draw a circuit consisting of 3 // cells // 1 switch and 2 bulbs // 1 switch and 2 bulbs.

 

 

 

 

 

 

 

 

 

 

Checked
l-I—l 0|
rr
_oj
Checked

 

A circuit consisting of 3 series cells // 1 switch and 2 bulbs // 1 switch and 2 bulbs.

 

 

 

 

Checked

 

 

r

 

*

 

[oHil

 

 

Checked

61

Circuit D:
Draw a circuit consisting of 2 cells // 1 switch and 3 bulbs // 1 switch and 1 bulb.

 

 

 

 

Checked

 

 

 

 

 

Checked

62

Physical Science: Physics Hour Number _
Electricity Name
B 11 Activity 7: Resistance Date
Ammeters are used to measure current (I) in units of Amperes, abbreviated amps or A.
You will use an ammeter to find the amount of current in different circuits so that you can
calculate the resistance in the circuit.

The purpose of doing this activity is to determine the resistance of wires in
relationship with the wire’s thickness and length.

You will need: 1 wire resistance board 1 ammeter 4 wires
2 cells wired in series 1 lamp and bulb

There are five different wires wrapped on the wooden spool.

Wire No. 1 10 meters long 22 gauge copper wire

Wire No. 2 10 meters long 28 gauge copper wire

Wire No. 3 20 meters long 22 gauge copper wire

Wire No. 4 20 meters long 28 gauge copper wire

Wire No. 5 10 meters long 22 gauge copper-nickel wire
Procedure:

1. Wire the 2 cells in series.

2. Attach 2 wires to the lamp and check to make sure that your bulb is working
and gives off a fairly bright light using 2 cells.

Attach one wire from the lamp to one of the terminal posts for wire number 1.

Attach the other wire from the lamp to the negative end of the cells in series.

Attach a wire from the positive end of the cells to the post marked with a (+).

Attach the last wire to the post marked low on the ammeter and to the other
terminal post for wire #1.

Repeat this procedure by moving the wires connected to the terminal posts for
each wire on the board.

Compare the brightness of the bulbs on a scale of 1 to 10, 10 being brightest.

99:55”

>1

9°

Ammeter Reading Description of wire Brightness Ratin r

 

 

 

 

 

 

 

 

 

 

 

 

 

 

8.) Rank the wires in order according to their resistance.

 

 

Most Resistant Least Resistant

63

Physical Science: Physics Hour Number_

Electricity Name

B 12 Activity 8: Date
Drawing Circuits & Using Ohm’s Law

Ohm’s law Formula: I = V -:- R Power Formula: P = V x I

 

 

Circuit #1: 3 cells in series // 2 bulbs and 1 switch in series
// 2 bulbs, 1 resistor and 1 switch in series
// 1 switch, 2 bulbs, 1 resistor and 1 switch in series.

Nmnber each series, one to three, from left to right.

Calculate the current and power in each of the series circuits within circuit #1.

Each cell has a voltage of 1.35 V, each resistor is rated at 4.25 ohms and each bulb has a
resistance of 1.8 ohms.

 

 

 

 

 

Series #1:
Givens Formula Calculations
Current
Power
Series it;
Civens Formula Calculations
Current
Power
Series #3:
Givens Formula Calculations
Current
Power

 

64

Circuit #2
4 // cells // 3 bulbs and 1 switch // 2 bulbs, 1 switch and l resistor.

Letter the two series circuits A and B.

Calculate the current and power in each of the series within circuit #2.

Each cell has a voltage of 1.5 V, each resistor is rated at 3.5 ohms and each bulb has a
resistance of 0.8 ohms.

 

 

 

Series A;
Givens Formula Calculations
Current
Power
Series B:
Givens Formula Calculations
Current
Power

 

65

Circuit #3: 4 cells in series // 3 bulbs and 1 switch // 1 switch, 2 bulbs and
1 resistor// 5 bulbs, 1 switch, 1 resistor, 2 bulbs and 1 switch.

Number each series, one to three, from left to right.

Calculate the current and power in each series within circuit #3 when each cell has a
voltage of 1.55 V, each resistor is rated at 2.5 ohms and each bulb has a resistance of 1.2
ohms.

 

 

 

 

 

Series #1:
Givens Formula Calculations
Current
Power
Senegal;
Civens Formula Calculations
Current
Power
Series #3:
Givens Formula Calculations
Current
Power

 

66

Physical Science: Physics Hour Number
Unit 3: Electricity Name
B 13 Homework #2: Circuits & Ohm’s Laws Date

 

1. Electricity is

 

2. A circuit is

 

A. How is a series circuit different from a parallel circuit?

 

 

B. How is a series circuit similar to a parallel circuit?

 

 

3. Identify each of the following as they related to the terms.
current, voltage, or resistance. Use the correct symbol for each quantity.

1. The quantity that is measured in ohms.

 

2. The quantity that is measured in volts.

3. The quantity that is measured in amperes.

 

4. The quantity that flows from negative to positive.

5. The rate at which charges pass a given point in a circuit.

 

6. The flow of charge past a certain point.

 

7. Is measured with an ammeter.

 

8. Describes a potential difference between two different positions.

 

 

9. The quantity that opposes the flow of electric charge.

10. A property of wire depending on the material, of which the wire made.

 

11. A property of wire that can vary with the temperature of wire.

 

 

12. A property of wire that depends on the length and gauge of a wire.

67

4. What happens if one bulb is removed or broken in Figure 12? (when the switch is closed)

 

 

 

firth

 

5. Use figure 1 and calculate the amount of current that
will flow given the following:

Ohm’s law F orrnula: V = I x R Label the values on fi e 1 and show our work below.
Each cell has a potential difference of 1.5 volts.

Each bulb has a resistance of 0.8 ohms.
Each resistor has a resistance of 6 ohms.

Figure 12

 

Answer:
6. Which switches in figure 13 would have to be closed to get bulbs A and B to light up?

 

 

 

 

 

 

 

 

, /
l 2
J. _L C
__ 2]: —— A
7. Which switches in Figure 13 would have to A B C ‘ D
be closed to get bulbs C, D and E to light up?
E
/3 B
8. If all three switches are closed and bulb D Figure 13

is taken out or broken, what would
occur with each of the remaining bulbs?

 

 

9. Using Figure 13, .
calculate the potential difference across the circuit when switches 1 and 3 are closed.
Ohm’s law Formula: V = Ix R Label the values on figure 2 and show vour worl_( below.
A current of 0.20 A is flowing through the circuit.

Each bulb has a resistance of 0.8 ohms.
Each resistor has a resistance of 6 ohms.

Total Voltage =

 

What is the voltage of each cell? A B C

68

Drawing Circuits
10. Draw each circuit with the parts listed. Make your drawings NEAT!!!

Circuit A: 3 //cells // 3 bulbs, 1 switch and 1 resistor in series // 2 bulbs,

l resistor and 1 switch in series // 1 switch, 2 bulbs and 2 resistors in
series.

Circuit B: 4 series cells // l bulb, 1 switch and 1 resistor // 2 bulbs, 2 resistors
1 switch // 1 switch, 3 bulbs, l resistor and 1 switch in series.

69

Physical Science: Physics Hour Number _
Magnetism & Electricity Name
B 14 Activity 5: Magnets Date

 

 

What happens when you put two magnets next to each other?

Sometimes there is a force between the magnets.

This experiment will help us understand and describe what happens when we put magnets
together.

Take two of the magnets and try the following experiments, write down what you see.

1: Try holding two magnets with their south poles facing each other. What happens?

Ciii

 

 

 

2: Try holding two magnets with their north poles facing each other. What happens?

15%

  

HT_/’_

 

 

3: Try holding two magnets with north and south poles facing each other. What happens?

Ga #3::

 

 

70

4: Write a rule stating how the force between the magnets behaves for the three

experiments.

The rule should use the following words: attract, repel, north, south, and pole.

 

 

 

5: How far does the magnetic force reach?
This is an important question for machines using magnets.

Place one magnet on the black rectangle on the ruler printed below. Slowly slide a
second magnet closer and closer until the first magnet moves. Record the distance
between the magnets when you first see movement. Do this three tries with the same
magnet. Your results should be pretty close for all three tests. Conduct the three tests
with each of the three combinations of poles, North-North, South-South, and North-

 

South.

 

r
. I
p.

 

 

 

llll llll

 

 

 

 

0

10 20

30 40

50 60 70

80

90

100 110

Distance in millimeters, marks are approximately 2 millimeters apart.

6: Does the distance change much between the three kinds of interactions (N-S, N-N, S-S)?

 

distance

 

 

 

 

 

Slide the secan magnet
{zioset and (In—r urstil
the firm one moves.

 

 

 

 

 

 

 

Z First megrzet

Second magr er

 

N-S

"i
F

W

Clarinet
5:] qul

8.8
m

ClAtuact
IRepel

N-N

E

Bartram
I IRcPd

 

Distance 1

 

Distance 2

 

Distance 3

 

 

 

 

As seen on student worksheet.

Explain your answer. Your answer should use the words force and distance.

 

 

 

71

 

Physical Science: Physics Hour Number _
Magnetism & Electricity Name
B 15 Activity 10: Strength of Magnets Date
1. Do magnets have different “strengths”?

 

 

Test to determine if more than one magnet placed together is stronger that one single
magnet. Then test to see if some of the other types of magnets are stronger or weaker
than the original magnets that you used.

 

 

 

 

 

 

 

 

 

 

, 90

0 10 20 30 40 50 60 70 80 100 110
Distance in millimeters, marks are approximately 2 millimeters apart.

 

Slide the magnet Number of Distance

or magnets along for Different Ma nets
the measuring Magnets Movement g

 

strip until the

single magnet on diSt- 1

 

the black space
moves. Record dist. 2
how far away the

 

inter i .
act on dr st. 3
occurs.

 

dist. 4

 

 

 

 

 

 

 

 

2. What did you find out about different numbers of magnets and how it affects the

strength of magnets? Your answer should apply the words force and distance.

 

 

 

 

 

72

Physical Science: Physics Hour Number _

Magnetism & Electricity Name

 

B 16 Activity 11: Magnetic Materials Date

 

1. What kinds of things are affected by magnets?
Not all materials interact with magnetic forces.
Use your test magnet to try ten materials around the classroom.

Record whether there was an attraction, repulsion, or no effect.

 

Material Tested Attract Repel

No Effect

 

y—L
O

 

 

 

 

 

 

 

 

PP°NQEAPP°P

 

y—A
53

 

 

 

 

 

2. The word magnetic is used to describe things that are strongly affected by magnets.

From your experiments can you say anything about which things were magnetic and

which were not? Your answer should apply the words magnetic and non-magnetic.

 

 

 

73

 

3. Do magnetic forces get weaker or stronger passing through non-magnetic materials?
Test some non-magnetic materials and see.

Start with a magnet at the end of the ruler below. Slide a second magnet in from the
end of the ruler, coming closer and closer until the first magnet just starts to move. Record
the distance at which the first magnet moved under the column "No Sample". Put your test
material in front of the first magnet and repeat the experiment. Enter the distance with the

sample in place under the column "With Sample". Try at least 5 different materials.

Slide the second magnet
58le e closer and closer until
= the first one moves.

F1] min

First magnet

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Second magnet
As seen on student worksheet.

lllllll n I ll

10 20 30 40 50 60 70 80 90 100 110
Distance in millimeters, marks are approximately 2 millimeters apart.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Material Distance With Distance Without
Sample Sample
1 .
2.
3.
4.
5.

 

 

 

 

 

74

4. What did you find out about how magnetism is affected by non-magnetic materials?

Your answer should apply the words force and distance.

 

 

 

 

5. How strong is the magnetic force acting on magnetic objects other than magnets?

You probably found that some materials are attracted to magnets. We call these magnetic materials.
Pick something small that is magnetic and try to find the distance that the magnet can move (or be
moved by) your magnetic object. Try both the north and south poles to see if there is a difference.

Slide the magnet
closer and closer until
the magnetic object moves.

“‘31,
FE lair/riff
I distance I

Magnetic object

 

 

 
  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Magnet
As seen on student worksheet.

 

 

 

 

 

 

 

 

 

 

llllllllllllllllllllllllllllllllllllgllllllll Ill

0 10 20 30 40 50 60 70 8 100 110
Distance in millimeters, marks are approximately 2 millimeters apart.

75

 

Distance at which Distance at which
Object object moves object moves

(south pole) (north pole)

 

 

 

 

 

 

 

 

+959

 

6. How does the magnetic force acting on magnetic objects compare with the magnetic
force acting on other magnets? Use the following words in your answer: force, magnet,

and magnetic.

 

 

 

 

76

 

Physical Science: Physics Hour Number_
Magnetism Name
B 17 Activity 12: Magnets & Magnetic Fields Date:

Obj. #3: The student will be able to describe how magnetism, magnetic fields and
magnetic poles interact and how they relate to motors, generators, and transformers.

 

Purpose: To visualize the invisible magnetic field around a magnet.

Get a compass and a bar magnet. Place the magnet on the table and start with the
compass in any one of the positions shown in the drawing below. From the first position
draw the needle position on the compass in the picture. Then move the compass around
the magnet to the seven other positions, each time drawing in the needle’s position.

0 O o
0E1 le
O O O

 

 

The ‘N’ stands for on the bar magnet.

The ‘8’ stands for on the bar magnet
From your observations:

Look at your compass. One end of the needle is colored and the other end is silver.

Which end of the compass needle points to the ‘N’?

 

Which end of the compass needle points to the ‘S’?

 

What happens when two north poles are brought close together?

 

What happens when two south poles are bought close together?

 

What happens when two opposite poles are brought together?

77

Iron, nickel, and cobalt are the only pure metal elements that are magnetic. Any metal
objects that have some iron, nickel, or cobalt will also be attracted to a magnet. Atoms
of magnetic materials are arranged in groups called domains. Each domain is made up of
one positive charge and one negative charge. Look at the diagram below. Block A shows
7 domains in each block. Block A has domains arranged so that each positive is next to a
negative charge. This iron bar is not a magnet. Block B show 10 domains and each
block is arranged in the same repeated pattern creating a magnet.

 

+-+ - + -+ <----BlockA +- +- +- +- +—

 

 

+- +- BlockB---> -+ -+ -+ -+ -+

 

 

 

 

 

 

 

 

 

 

 

 

 

In order for an object to be magnetic, the domains must be lined up in the same direction
as shown in block B. When the domains are lined up and the object acts as a temporary
magnet. The alignment of the domains is the situation occurring in permanent magnets.

Find the strongest points of the magnetic field that surrounds a bar magnet.

Use paper clips as masses. Hang as many paper clips as you can from the magnet in the
five positions shown in the picture at the right.

Predict where do you think the bar magnet will be strongest.

 

 

 

 

Write the total number of paper clips held in each of the positions on the magnet above.

From your observations, where are the strongest positions along a bar magnet?

 

78

The magnetism from a magnet can be transferred to other iron containing objects.

Use a nail and a bar magnet. Rub the nail along the bar magnet slowly, in one direction,
about 25 to 30 times. Then bring the nail close to a small paper clip.

What do you observe?

Rubbing the nail over the magnet causes the in the nail to line up.

Place a bar magnet under the plastic magnet viewer.

Observe what is happening to the iron filings.

The magnetic field around a magnet is where the magnetic forces are observed. We
cannot feel or see the magnetic field, but we can see what happens when we use iron
filings, small bits of iron, that are attracted to the magnet and line up in the magnetic
field. Sketch a simple depiction of what you observed on the magnet below.

 

N S

 

 

 

Observe one of the two plastic containers that have a cow magnet inside.

The small iron pieces inside the plastic case are attracted to the magnet and position
themselves along the magnetic field lines. Make a simple sketch of what you observe.

 

C:

 

 

 

In your observations, where did you see more iron filings around the two magnets?

 

79

Answer the following questions from what you have read and done.

1.) Magnetism is caused by

 

 

2.) What three metals are magnetic?

A B C

3.) In order for a piece of iron to be a magnet, its must be lined up.

4.) A bar magnet is strongest at its

 

5.) What is the magnetic field?

 

 

6.) Which statements are true?
Some magnets are made of lead.

Some magnets are made of cobalt.

Lines of magnetic force run from one pole of the magnet to the other pole.

Lines of force are strongest at the center of the magnet.

7.) Predict what the lines of force would look like for the situations below.

Draw in the magnetic field lines as they would look for both situations.

 

 

 

 

 

 

N S

 

 

 

 

 

N N

 

 

 

 

 

8O

Physical Science: Physics Hour Number_.
Magnetism Name
B 18 Activity 13: Electromagnets Date:

Obj. #3: The student will be able to describe how magnetism, magnetic fields and
magnetic poles interact and how they relate to motors, generators, and transformers.

 

Materials: One-150 cm length of coated wire with the ends stripped off.
1- Iron Nail 4- D-cells Paper clips l-Bar magnet
Magnets and Electromagnets

1. Coil the wire tightly 25 times around the nail, leaving a length of wire on
each end of the coil long enough to reach the battery.

2. Connect the ends of the wires to a 1.5 volt battery.
3. When the circuit is completed, the electromagnet will be on.

4. Try to pick up as many paper clips as possible with this electromagnet.
Repeat this step 2 or 3 times.

5. Complete the data chart on the following page, noting how many paper
clips this electromagnet lifis.

6. Repeat steps 2-5, adding one battery to the magnet at a time until you reach have
all four batteries hooked together.
Use a masking tape to connect multiple batteries together.

7. Coil the wire tightly 25 more times around the nail (for a total of 50 tums),
leaving a length of
wire on each end of the coil long enough to reach the battery.

8. Repeat steps 2-6 for this new electromagnet.

9. Experiment with a bar and horseshoe magnet from the supply table.
How many paper clips does this magnet pick up?
How does the permanent magnet interact with the electromagnet?

**BE CAREFUL: THE WIRES MAY BECOME HOT DURING USE“

DISCONNECT THE MAGNET FROM THE BATTERY
WHEN YOU ARE NOT TESTING THE MAGNET'S STRENGTH!

81

Magnets and Electromagnets - Questions for Discussion
Directions: Answer the following questions about what you discovered.

1. Does it make a difference where the windings are located or how neat the wire is wound?

2. How does it change the electromagnet to increase or decrease the number
of turns of wire?

3. How does the electromagnet compare with a permanent magnet?

Which did you determine to be stronger?

How do the two interact?

4. Write any questions you have about electromagnets.

82

 

Physical Science: Physics Hour Number
Electricity & Magnetism Name
B 19 Activity 14: How a Motor Works Date

1. Electric motors are everywhere. Name five appliances or tools (or places) you know
where there is an electric motor and briefly state what the motor does or what the
motor causes to happen.

 

 

 

 

 

2. Take your Electric Motor apart and set it up like the picture shows.
0 The rotor should be uncovered and empty of magnets.
0 Put six magnets in the rotor evenly spaced with north and south poles alternating
around the edge.
0 Take another magnet and bring it close so that it repels a magnet in the rotor.

o What happens? Try to come up with a way to make the rotor spin using your single
magnet and pushing and pulling on the rotor magnets.

Hold a magnet closeand try
Remove the big nut and . _. l to make the rotor spin.
colored program disc to " - .
show the magnets. ’

  
 

North and south poles
should alternate facing out.

As seen on student worksheet.

83

3. How did you get the rotor to spin in one direction?

What did you have to do with your extra magnet?

 

 

Electromagnets are magnets that use electricity
to create the north and south poles. When no
electricity flows, they are not magnetized. Look
at one of the Electromagnet Modules. You will
see a coil of coma wire wrapped around a thick
steel pin. That is how an electromagnet is usually
made, a coil of wire wrapped around a steel or
iron core. The coil of wire is where the
electricity flows. When electric current flows
around the coil, the steel pin becomes
magnetized with a north and south

pole, just like your other magnets.

Electromagnets have a big advantage
over permanent magnets. By
changing the direction of the electric
current we can reverse the north and
south poles. The fingers of your right
hand can tell you where the north
pole will be if you know the direction
of the current.

  

Etectromasnet Mod ule

—r-"'“""\

...._.-l"'" 55?, .‘;?h

\— Cc=il of wit:
Thick: steel air:

As seen on student worksheet.

The nght Hand Rule

9M‘\

 

Electric
Current

 

 

The Electromagnet Modules have a
light switch, like the Photogate Clamp.
Blocking the light beam makes the
current reverse direction in the coil of
wire. The little green lights tell you where the north pole is.

As seen on student worksheet.

- Can you think of an important reason why the north and south poles

have to switch in an Electric Motor?

84

Infra-rod
light beam

4. Find the orange disc, which has three black spaces and three clear spaces around the

  
   

The light tells you
where the north
pole is.

 

 

As seen on student worksheet.

edge. Put the disc on the rotor like the picture shows. Make sure that the
boundaries from black to clear line up with the centers of your six magnets!

   
   

blackfclear edge

The edge from black
to clear must line up
with the magnets or the
motor wrll not work well.

Use the big nut and white
plastic washer to hold the
orange plate down.

As seen on student worksheet.

Put one electromagnet on the Electric Motor and GENTLY tighten down
the thumb-nuts to hold it in place and make electrical contact.

Connect the battery pack with the red (+) wire in the red (+) socket
and the black (-) wire in the black (-) socket.

Push the RUN button and give the rotor a push to start it spinning.

You should have a working electric motor!

85

You mighthmem DU-‘Shlhe -\ \. ' a, I

\ o

 
      
 

 

As seen on student worksheet.

5. Why does it work? Where is the north pole when the disk is in the following positions?
Try the experiment and find out. Circle the correct olari for each icture.

 

Black edge under the
Electromagnet

 

( _ . ' .6." ' ' Circle the right polarity
Clear edge under the
Electromagnet
-'.~ omni-
. I 'er' ' I Circle the right polarity

a n
nnnnnnn

As seen on student worksheet.

86

6. Suppose you have a rotor with magnets like the ones in the picture below.
The electromagnet has a north pole facing in towards the rotor. Which way will it turn?
Circle the ri ht direction.

 

CCCQCs

”SSW .\
©\ @@ Electromagn at

As seen on student worksheet.

 

7. How can you make your motor spin the other way?
Find a way to make the motor spin the direction you choose.
What did you have to do?

 

 

87

Physical Science: Physics Hour Number _
Electricity & Magnetism Name
B 20 Class Warm-up 4: Rotating Motors Date

 

 

.....
a ‘ ' .

Ol'

thunterclockwl'js‘e/ \blockwis.e:.

cps-ecu.

6%- xv“...
' given»

    
  
  

Electromagnet

  

A)
\E ,.

 

As seen on student worksheet.

88

Physical Science: Physics Hour Number __
Unit 4: Electricity & Magnetism Name
B 21 Activity 15: How fast does a Motor Turn Date

What makes a good electric motor design? Of course, a motor must turn to be a good design.
But, there are other considerations. Some other important things to consider are:
- What is the maximum speed of the motor?
- How much torque (rotating force) does the motor develop?
- How reliable is the motor? Does it always start?

Testing for Performance

When building a new machine we always try to build the best possible design given the
materials and constraints. One way to tell the best design for the electric motor is to measure
the speed of the motor and try to design the fastest motor that gives the highest speed. We
can compare different designs to evaluate which is best by comparing the speeds. The speed
of the motor is measured with the Timer and Photogate Clamp. Attach the Clamp to the
motor in the slot at the top as shown in the diagram. If the Clamp is pushed in as far as it
will go, the black parts of the switching plate will break the light beam in the timer. This is
how we measure the speed of the motor.

 

  

Attacring the
Photogate Clamp

 

 

As seen on student worksheet.

89

Using Frequency Mode

In frequency mode the Timer measures the number of times per second that the light beam
is interrupted. Use only one Clamp attached to input "A". In frequency mode the "A" button
controls the measurement much the same way as in stopwatch mode. Use the "A" button to
toggle the "A" light on and off.

0 When the A light is on the Timer measures frequency and updates the display every
two seconds

0 When the A light is off the Timer displays the last frequency measurement and freezes
the value.

The Timer measures frequency in kilohertz (kHz). To convert to cycles/second
(Hertz) you must multiply the Timer reading by 1000. This is the same as shifiing the
decimal point three places to the lefi.

1 kHz = 1000 cycles/second = 1000 Hz.

A frequency of 20 Hertz means that the light beam is being broken 20 times per second.
How does the frequency of breaking the light beam tell us the speed of the motor?
The answer depends on the switch plate being used.
For the 4 pole switch plate the light beam is broken 2 times for each turn of the rotor.

The rotation speed of the rotor is the frequency divided by the number of black
segments on the switch plate.

 

Most electric motors are specified in terms of RPM, or
revolutions per minute. To be a good comparison we
need to convert our speed measurements (in rotations or
revolutions per second) to rpm (revolutions per minute).

 

 

 

 

If the motor turns 20 times per second, and there are

 

60 seconds in a minute, then the speed of the motor is Measurement [3 .020 kHz
20 rev/s x 60 s/min. = 1,200 rpm. in 0.020 x 1m0

20 Hz (20 cycleslsec)

Example Calculation As seen on student worksheet.

The 6 pole switch

plate has 3 black segments around the rim and
therefore breaks the light beam 3 times per
revolution. The rotation frequency for this plate
would be the frequency measured by the Timer

 

divided by three.
The 6 Pole Timer measurement: 0.033 kHz = 33 Hz
SWitCh Plate Rotor frequency = 0.033 x 1000 + 3 = 11 rev/s
As seen on student (revolutions per second)
worksheet.

Rotor speed = 11 rev/s x 60 s/min. = 660 rpm

90

 

 

B4.1: Calculate the rotation speed of the motor fiom the given measurements for practice.

Check your answers to be sure you know how to calculate the speed. Then complete your
own measurements with the photogate and calculate the actual speed of the different motor
configurations.

 

Timer Reading Rotation Rotation
Switch Plate (kHz) Frequency In Speed in
Cycles/Sec (Hz) RPM

 

0.012 kHz

 

Pole Your Timer Reading

 

0.024 kHz

 

Pole Your Timer Reading

 

0.061 kHz

 

Pole Your Timer Reading

 

0.015 kHz

 

Pole Your Timer Reading

 

0.053 kHz
12

Pole Your Timer Reading

 

 

 

 

 

 

 

 

 

Conclusion:
1. What is the maximum speed of the motor?

 

2. Did the motors always start on their own? Which ones did?

 

Which ones didn’t?
3. Which motor design was the most reliable?
Which motor started rotating with the least assistance?

 

 

91

Physical Science: Physics Hour Number
Unit 4: Electricity & Magnetism Name
B 22 Activity 16: Intro to Transformers Date

 

Use the computer to look up the article: “Inside a Power-Cube Transformer” at the
following address: http://www.howstuffworks.com/inside-transformer.htm

Read through the information and look at the pictures of the transformer that has been taken
apart.

How many of those little Power Cube thingies do you have around your house?

1. What do the windings refer to?

 

2. What is the purpose of a transformer?

 

 

3. The 120 volts comes in on the

 

4. The AC current in the primary winding creates an

 

 

5. In this case the transformer converts

 

6. If the primary and secondary windings have the same number of turns,

the primary and secondary voltage

 

7. If the secondary winding has half as many turns as the primary. then the voltage in the

 

 

secondary that of the voltage in the primary.
8. To drop down to 3 volts, there needs to be more turns in the
primary than in the secondary.

92

Physical Science: Physics Hour Number
Unit 4: Electricity & Magnetism Name
B 23 Activity 17: Transformers & Voltage Date

 

Observe the three different transformers that are disassembled on the back table.

Transformer A:
1. How can you determine the primary windings from the secondary windings?

 

2. How can you determine whether this is a step-up or step-down transformer?

 

3. Is this a step-up or step-down transformer?

 

Transformer B:
1. Are there more primary windings or secondary windings?

 

2. Is this a step-up or step-down transformer?

 

Transformer C:
Follow the plug-in cord to the transformer.

1. The side of the transformer where the cord enters would be the coil.
Power companies use transformers to increase the voltage and transformers near your home

are used to decrease voltage. Sketch the turns of wire to represent transformers on the
figures below. Label the primary and secondary windings on both pictures.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Step-up Transformer Step-down Transformer

93

l. A is a device that the voltage in a circuit.

2. A step-up transformer

3. A step-down transformer

4. Figure 3 shows an example of which type of transformer?

 

 
   
  
 

Secondary

5. What is the turn ratio of the transformer in winding winding
Figure 3? 500 turns 5000 turns
110 Volts ? volts

 

6. What is the resulting voltage in the secondary
coil in figure 3?

 

7. Figure 4 shows an example of which type of transformer?

 

 

 

 

 

Primary coil Secondary coil
8. What is the ratio of the
- ‘7 turns 2000 turns
tr f 4? '
ans orrner in figure 800 Volts 20 Volts
9. Calculate the number of turns in the primary coil in figure 4?
10. Figure 5 shows an example of which type of transformer?
P ' 'l S d 'l
11. What is the ratio of the rrmary cor econ ary cor
transformer in figure 5? 1000 Volts 100 Volts
300 turns ? turns

 

 

12. Calculate the number of turns in the secondary coil in figure 5?

 

94

Physical Science: Physics Hour Number
Unit 4: Electricity and Magnetism Name
B 24 HOMEWORK #3 Review Date

 

1. If each cell in Figure 1 has a voltage of 1.5 volts, what is the total voltage in the circuit?

2. Which switches, in Figure 1, would need to be
closed in order for bulb G to light up? .fl/ @-
A 1 B

3. Which switches, in Figure 1, would need to be 4 \
closed in order for bulb E to light up? @ C

F E 3@D

 

 

 

 

 

4. Calculate the current flowing through the circuit in
Figure 1 if ONLY switch one is closed.
Show your calculation!

 

Givens
Each cell is rated at 1.5 volts.
Total Voltage = Each bulb has 2.3 ohms of
. resistance.
Number ofbulbs 1" = Each resistor has 5 ohms of
resistance.
Total Resistance =
Formula Calculation
Current =

 

5. Calculate the current flowing through the circuit in Figure 1 if ONLY switches two and
four are closed. Show your calculation!

Givens Formula Calculation
Total Voltage =
Number of bulbs lit =

Total Resistance =
Current =

95

6. What is the total voltage in figure 2?

 

 

 

 

 

 

 

 

 

A
, © /1
'0
7. Which switches, in Figure 2, _J_ _l_ —_J:- B D OF
would need to be closed —_ "" 2
in order for bulbs F, G @G
and H to be lit? 3
/ pC E @H
4 ,

8. Which switches, in Figure 2,

would need to be closed Each cell is rated at 1.5 volts.
in order for bulbs D and E Each bulb has 2.3 ohms of resistance.
to be lit? Each Resistor has 5 ohms of resistance.

 

9. For Figure 2, if bulbs D and E light up, what other bulbs will be lit up?
List them ALL!

 

10. Calculate the current flowing through the circuit in Figure 2 if ONLY switches
3 and 4 are closed. Show your calculation!

gm Fo_rmu_la Calculation
Total Voltage =
Number of bulbs lit =
Total Resistance = Current =

 

l 1. Calculate the current flowing through the circuit in Figure 2 if ONLY switches
1 and 4 are closed. Show your calculation!

m _Fo_rm_ul_a Calculation
Total Voltage =
Number of bulbs lit =
Total Resistance = Current =

 

96

12

13

14

15.

16

17.

18

. The transformer in Figure 3 shows an incoming voltage of 1000 volts and an outgoing
voltage of 100 volts. What type of transformer would this represent?

 

 

Primary coil Secondary coil
1000 Volts 100 Volts
. What is the ratio of the voltages? 300 turns ? turns
___anPfim to $29M
volts to __volts Figure 3

What is that same ratio in lowest terms?

 

. From the ratio of voltages, what can you determine to be the ratio of the turns
of wire wrapped around the iron core of the transformer?

 

 

 

 

 

 

The transformer in Figure 4 shows what type of transformer?
Primary coil Secondary coil
50 turns 300 turns
9
. From the ratio of turns of wire, 1 10 VOItS ' volts
determine the ratio of the voltage
for the secondary coil. Figure 4
Ratio of turns =
Secondary voltage =
The transformer in Figure 5 shows what type of transformer?
Primary coil Secondary coil
? turns 2000 turns
10,080 Volts 240 Volts

. From the ratio voltage determine the ratio of
the number of turns of wire for this

 

Ratio of voltage =

Primary coil number of turns of wire =

 

97

19. Label the picture showing which direction the rotor will turn and the repulsion and
attraction positions between the permanent magnets and the electromagnet.

 

Li I

Electromagnet

 

20. What makes a motor turn?

 

 

21. If all three of the electromagnets had their north pole pointing in toward

the rotor, which electromagnets would be working together to turn the motor
clockwise?

 

22. Would this motor work the way that is it set up?
Why or why not?

Position #1

 

Electromagnet

 

 

 

 

e
5’06,

As seen on student worksheet.

98

Physical Science: Physics Hour Number _
Unit 4: Electricity & Magnetism Name
B 25 TEST Date

Objective #1 : The student will be able to define electricity, in terms of circuits, and discuss
the relationship among voltage, current, and resistance within different circuits and
calculating values within a circuit using Ohm’s law.

 

 

 

 

1. Calculate the current flowing through the circuit
in Figure 1 if ONLY switch one is closed.
A. 1.02 A B. 0.98 A 2
C. 0.98 v D. 0.33 A 4 \A
2. Calculate the current flowing through S§2 /3_ ©C
the circuit in Figure 1 closing E
ONLY switches 2 and 4. F © @ D
A. 0.32 A B. 0.98 A
C. 0.49 A D. 0.38 A —-W—&‘
3. The unit used to measure electric current is the Figure 1
[8‘ amp 3811:“ Each cell is rated at 1.5 V.
' a“ - 0 ‘ Each bulb has 2.3 ohms of
' t .
4. Potential difference or voltage rs measured 1.3:: if; or has 5 ohms of
in the unit called a(n) resistance
A. ampere B. ohm. '
C. watt D. volt.

5. The opposition to the flow of electricity or current is called
A. amperage. B. resistance.
C. electric current. D. voltage.

6. According to Ohm’s law: I = V/R.

If the resistance in a circuit is increased current
A. stays the same B. decreases

C. increases D. doubles

7. If the voltage within a circuit is increased the current will
A. stay the same B. decrease
C. increase D. double

8. The unit of measurement for resistance is the—
A. ampere. B. ohm.
C. watt. D. volt.

99

 

9. AC current is electricity that
A. alternates the flow of voltage B. alternates the parallel paths of current.
C. alternates the resistance. D. alternates the direction of the current.

10. For electricity to flow through a circuit, the switch must be
A. open. B. in series. C. closed. D. in parallel.

11. Batteries (cells) provide the potential difference or __ to make current flow.
A. amperage B. resistance C. electric current D. voltage

12. Calculate the current in Figure 2 if ONLY
switches 3 and 4 are closed.

 

 

 

 

 

 

A
A. 0.13A B. 14.4A © /1
C.0.16A D. 11.9A 4_ __ B D F
E. 0.38A —_ :1- —_ 2
G
3 F
E H
/4 F39 ,
Figure2

Each cell is rated at 1.5 volts.
Each bulb has 2.3 ohms of resistance.
Each Resistor has 5 ohms of resistance.

13. Calculate the current flowing through the circuit in Figure 2
if ONLY switches 1 and 4 are closed.
A. 0.13 A B. 14.4A C. 0.16A
D. 11.9 A E. 0.38 A

14. Calculate the current that would flow through the circuit in figure 3.

A. 0.86 ohms B. 7 ohms
C. 6 volts D. 1.2 A
E. 0.86 A A B C

1.5 ohms 2 ohms 1.5 ohm

Figure 3

100

Objective #2: The student will be able to identify parts within an electrical circuit, diagram
and construct circuits and identify properties associated with series and parallel circuits.

15. What is the total voltage of the cells in Figure 1?
A. 1.5V B. 3V C. 4.5V D. 4.5A

16. Which switches MUST be closed in Figure 1 in order for bulb F to light up?

 

 

 

 

 

 

A. 1,2and4 B.2and4 C.3and4
D. 1and3 E.1,2,3and4
17. Which switches MUST be closed in Figure 1 in order for bulb E to light up?
A. 1, 2 and 4
B. 2 and 4 C. 3 and 4 A
D. 1and3 E.2,3and4 Q /1
__ __ _L B D F
18. What is the total voltage of the _7- __ 2 G
cells in Figure 4? 3
A. 1.5V B. 3V bc FE H
C. 4.5 A D. 4.5 v /4
19. Which switches MUST be closed Figure 4
in figure 4 in order for 9‘1le F, Each cell is rated at 1.5 volts.
G and H to be lit? Each bulb has 2.3 ohms of resistance.
A- 1, 2 and 4 B- 1 and 4 Each Resistor has 5 ohms of resistance.
C. 3 and 4 D. l and 3
E. 1, 2 and 3
20. Which switches MUST be closed in figure 4 in order for bulbs D and E to be lit?
A. 1,2and4 B. land4
C.3and4 D. 1and3 E.1,2and3

21. The cells in Figure 1 are wired in
A. parallel B. series C. unison

 

22. If the electric current can flow through different paths it is called a(n) circuit.
A. open B. parallel C. series D. transistor

23. An electrical circuit connected one part after another is called a(n)_ circuit
A. open B. transistor C. parallel D. series

 

24. Ifbulb B were removed in Figure 3, what would happen to bulbs A and C ?
A. Bulb A would remain lit.

B. Bulb C would go out, bulb A would stay lit.

C. Bulb B would go out, bulbs A and C would stay lit.

D. Bulbs A and C would both go out.

E. Bulbs A and C would remain lit.

101

Objective #3: The student will be able to describe how magnetism, magnetic fields and
magnetic poles interact and how they relate to motors, generators, and transformers.

25. A generator is a device that converts

A. heat energy into electrical energy.

B. electrical energy into heat energy.

C. electrical energy into mechanical energy.
D. mechanical energy into electrical energy.

26. The device that increases AC voltage as it leaves an electrical power

plant is called a(n)
A. AC transformer B. step-up transformer
C. AC galvanometer D. step-down transformer

E. step-up generator

27. The device that decreases AC voltage as it enters your CD player is called a
A. AC transformer B. step-up transformer

C. AC galvanometer D. step-down transformer

E. step-up generator

 

28. The device that decreases AC voltage as it enters your home is called a(n)
A. AC transformer B. step-up transformer

C. AC galvanometer D. step-down transformer

E. step-up generator

 

29. A motor is a device that converts

A. heat energy into electrical energy.

B. electrical energy into heat energy.

C. electrical energy into mechanical energy.
D. mechanical energy into electrical energy.

30. Figure 5 shows an example of a(n)

 

A. AC transformer _ . _
B. step-up transformer Primary corl Secondary corl
C. AC galvanometer 250 turns 50 turns
D. step-down transformer 100 Volts 17 Volts

E. step-up generator

31. What is the ratio in figure 5? Figure 5

A. 5:2 B. 2:5

C. 2:1 D. 5:1

32. What is the voltage in the secondary coil in figure 5?

A. 20 volts B. 25 volts C. 10 volts

D. 250 volts E. 100 volts

102

33. Figure 6 shows an example of a(n)

 

A' AC MSfomer Prim coil Second coil
B. step-up transformer ary ary
C. AC galvanometer 50 turns 300 turns
D. step-down transformer 110 Volts 7 volts
E. step-up generator
Figure 6

34. What is the ratio in figure 6?
A. 5:2 B. 6:1
C. 1:10 D. 1:6

35. What is the voltage in the secondary coil in figure 6?

A. 18.33 volts B. 3000 volts C. 11 volts

D. 660 volts E. 50 volts

36. The motor in Figure 7 would turn in which direction?

A. Clockwise B. Counterclockwise C. It would not turn at all.

 

Electromagnet

 

37. For the motor in Figure 7 to turn in a clockwise direction
what would have to be changed?

A. The direction of the electromagnet.

B. The magnets should have their north to pole to the outside.

C. The magnets should have their south to pole to the outside.

103

38. What makes the shaft of a motor rotate?

A. The force of attraction between the magnets and the electromagnets.

B. The force of repulsion between the magnets and the electromagnets.

C. The force of repulsion and attraction between the magnets and electromagnets.

D. The mechanical energy turns the shaft of the motor.

39 Which picture best shows the strength of the magnetic field for a bar magnet?

90990900000006 W No 0 0 0991

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Magnet B Magnet C
N E s 9 5'0 Sb
Magnet D Magnet E
Total points possible for the unit 4 test = 39 Your Score

104

Physical Science: Physics Hour Number
Unit 4: Electricity and Magnetism Name

B 26 Student Evaluation Sheet Date
Please help me by being honest and truthful when answering each question.

 

1. Please list and describe some of the information that you learned and found most
interesting during the electricity and magnetism unit.

 

 

 

 

 

 

2. What are some of the things you liked or enjoyed learning most about the electricity and
magnetism unit?

 

 

 

 

 

 

3. What are some of the things you liked or enjoyed learning least about the electricity and
magnetism unit?

 

 

 

105

4. What are some of the things that you did, activities or labs that helped you understand the
information about electricity and magnetism.

 

 

 

 

 

 

5. What suggestions would you offer to help me improve the electricity and magnetism unit?

 

 

 

 

 

6. Rate your knowledge of the topic before and after the unit was taught.
Place a “B” in the area that would relate to before the unit and an “A” for after.

No understanding Very little Understand Good
understanding fairly well understanding
1 2 3 4 5 6

 

7. Please make any other comments that you feel would be beneficial to me as a teacher.

 

 

 

106

REFERENCES

Beaty, Bill. (1994) “VDG Hints: Solving Humidity Problem”
<http://www.amasci.com/emotor/humid.html> (last visited: 7/2/2002).

Cambridge Physics Outlet. (1997). Electricity, Magnets, and Motors
Teacher’s Guide. Cambridge Physics Outlet, Inc.

Delisle, R. (1997). How to use problem-based learning in the classroom. Arlington:
American Association of School Administrators.

Gardner, H. (2000). Intelligence Reframed: Multiple Intelligences for the 213t Century.
New York: Basic.

Hyerle, D. (1996). Visual Tools for construction knowledge. Arlington: American
Association of School Administrators.

Jensen, E. (1998). Teaching with the Brain in Mind. Arlington: American Association
of School Administrators.

Parnell, D. (1995). Why Do [Have to Learn This?. Waco: Center for Occupational
Research and Development, Inc.

Sousa, D. A. (2001). How the Brain Learns. 2“d ed. Thousand Oaks: Corwin Press.

Stepans, J. (1996). Targeting Students ' Science Misconceptions: Physical Science
Concepts Using the Conceptual Change Model. Riverview, FL. Idea Factory,
Inc.

Wirt, S. (2002). “Charge Thefi.” Science Joy Wagon

<http://www.sciencej oywagon.com/physicszone/
lesson/07elect/static/thefi/theft.htm>.

107

General References

Gardner, H. (1983). Frames of Mind: The Theory of Multiple Intelligences. New York:
Basic.

Gardner, H. (1993). Multiple Intelligences: The Theory in Practice. New York: Basic.

Hart, D. (1994). Authentic Assessment: A Handbook for Educators. Menlo Park:
Addison-Wesley. '

Hull, D. ( 1995). Who Are You Calling Stupid?. Waco: Center for Occupational
Research and Development, Inc.

Rogers, S, & Graham, S. (2000). The High Performance Toolbox: Succeeding with
Performance Tasks, Projects, and Assessments. 3rd ed. Evergreen, CO: Peak
Learning Systems.

Steinberger, E. (1993). Improving Student Achievement. Arlington: American
Association of School Administrators.

Tobias, S. (1990). They ’re Not Dumb, They ’re Diflerent. Tucson: Research
Corporation.

108

   

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