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A Study of Understanding of Electric Circuit and the
Relation between Attitudes and Problem Solving Skill for
12nd Grade Engineering Science Classroom Students
Chanakan Chomngam
Office of Engineering Science Classroom, Learning Institute, King Mongkut’s University of
Technology Thonburi, Thailand
Abstract
The purpose of this study is to investigate students’ understanding of electric
circuits. In this study, we focus on problem solving dealing with electrical
circuits of 12th grade Engineering Science Classroom students. The learning
processes are modelled by the ESC program. We attempt to include the soft
skills such as problem solving, collaboration into the intensive electric course
to promote the attitude and to improve understanding of electricity of
students. Test is analyze have two main questions. In the first question,
students have to solve total resistance from four circuits. In the second
question, students have to solve more complex circuit in any point for this
circuit. Kirchhoff’s current law (KCL) and Kirchhoff’s voltage law (KVL) are
used to solve. The results for solving total resistance show that 70.3 % of ESC
student can correctly solve the total resistance. 26.92% misunderstanding
about the direction of the current in circuit, wrong perception in parallel
circuit and use wrong parallel formula. For the complex circuit which is used
KCL and KVL, only 23.08% can correctly solve problem. KCL concept is
poor. They cannot solve the current and then cannot analyze voltage each
loop. However, the total resistance solving is a basic for analyzing complexed
circuit. Finally, we found the relation between the attitudes of physics effects
the electric solving skill. The significant difference between attitudes and
groups of students who solve circuit and students who cannot solve is 0.005.
Keywords: electric circuit, problem solving skill, attitudes, MPEX,
misunderstanding
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Introduction
Engineering Science Classroom (ESC) is a Science Classroom in University
Affiliated (SCiUS) Program of the Ministry of Science and Technology,
organized by King Mongkut’s University of Technology Thonburi (KMUTT).
ESC has developed a new approach for learning science at the high school level.
ESC offers no specific classes of biology, chemistry, or science or art. All
learning topics are integrated into ‘stories’ that are categorized into 6 general
topics. The stories are designed based on the history of civilization, beginning
from the Stone Age to modern times. 6 general topics are contained in six
semesters in the three years of the students. In the fifth semester, the ‘story’ starts
when Alessandro Volta invented the first battery in the year 1800. The first
batteries cause scientists to realize that chemical reactions can lead to electricity.
Later, Michael Faraday created the first electric generator by using a magnetic
field in the year 1821. In the year 1879, Thomas Edison invented the light bulb.
This invention was highly valuable for other inventions related to electricity. In
the 19th century, electricity was used for lighting and generating power during the
war. In the first semester of 12nd grade, students learn about the development of
electricity. This story is a subject called “From wire to wireless”. “From wire to
wireless” includes mathematics, physics, and chemistry together. The contents are
integrated in topics such as electrochemistry, static electricity, direct current,
alternating current, magnetism and magnetic fields, semiconductors, transistors,
electromagnetic waves, and complex number used in alternating current. There
are various styles of teaching - lectures, demonstrations, experimenting and a
electrical project. This course is intended to promote the attitude of students and
to improve their understanding of electricity by hands-on activities.
Attitude is the one key to understanding physics. There are many researches
studying the attitudes of students [1, 2]. The Maryland Physics Expectation
Survey (MPEX) [3] was designed to probe students’ expectations and attitude
about their understanding of the process of learning physics and the structure of
physics knowledge. The MPEX is a survey consisting of 34 agree/disagree
questions to probe expectations. Expectations in the MPEX are divided into six
dimensions which are independence, coherence, concepts, association with reallife phenomena, application with math, and effort. The responses that showed an
ability to think like a physicist was called favorable, while responses that do not
show it are less favorable. A study to understand the attitudes is important. The
attitudes, belief and expectations affect the learning behavior and the
understanding of physics principles.
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Much of research on physics education studies the students’ understanding
and difficulties of topics in physics, such as vectors [4], forces and Newton’s laws
[5], heat and temperature [6], weight and mass [7], and electricity and magnetism
[8] In the topic of DC circuits, many researchers found misconceptions in concepts
of electrical current, resistance, potential difference, electric generators and
electrical energy [8][9]. Electric circuit is a basic topic covered from 8th grade until
university for Thai students. This topic is continuous, and so misunderstanding of
the basic concepts in middle school can lead to misunderstanding of more difficult
content [9]. The most common cause of misunderstanding is that most students try
to memorize formulas and remember which formulas fit with the type of problem
given. This shows that they do not fully understand electricity, but instead simply
memorize equations when solving physics problems.
Materials and Methods
26 students from the 12th grade, consisting of 10 males and 16 females,
participated in the research. When the students finished learning electricity and
electronics, they completed the MPEX and a DC circuit test. The test consists of
two parts. The first part consists of 4 problems, which are shown in figure 1. The
students have to find the resultant resistance from parallel and series circuits. The
second part asks the student to calculate the voltage and current at various parts of
a circuit. A question from the second part is shown in Figure 2.
(1)
(2)
3
(4)
(3)
Figure 1. The first part of the DC current test
Figure 2. The second part of the DC current test
Results and Discussion
The purpose of this work is to investigate students’ understanding about electric
circuits, with focus on how students solve circuit-related problems. The
relationship between the attitude in physics and ability to solve problems is
investigated. First of all, the attitude of students after finishing the subject “From
wire to wireless” is presented. The attitudes in 6 dimensions are presented in
Figure 3. In Figure 3, the y-axis represents the percentage of favorable responses,
and the x-axis represents the 6 dimensions of expectations. From the research, the
percentages of students whose responses were favorable were 26.26% for
independence, 51.11% for coherence, 25.31% for understanding of concepts,
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50.9% for association with reality link, 29.01% for application with math link, and
44.44% for effort, cumulating to an overall 40.6%. From the results, the
coherence and application with math dimensions are the most favorable. This
could result from the curriculum of Story-based learning. The integration of the
content and the subjects allow the students to link all related knowledge to
enhance their learning experience. The school aims to install an appreciation of
the importance of all contents and subjects, and how they interact and are related
to one another. The favorable response for coherence points to the students’
abilities to link different topics together, while the response for association with
real-life phenomena point to the students’ abilities to link what they have learnt
with what they see.
Figure3. The percentage of favorable responses for the 6 dimensions of expectations
for ESC students
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Table I. categories of misunderstanding to solve total resistance and percentage of
students in each category
Category
Description
Student %
a
Correct Answer
73.08%
b
Misconception of current direction
19.23%
c
Misconception with parallel circuits
3.85%
d
Wrong formula used
3.85%
e
Overall strong misunderstanding
3.85%
Table I presents 5 categories (a-e) of the students’ answers to Problem 1. This
problem is used to classify student s’ understanding of the electric circuit and
abilities to find the total resistance of the four circuits. The descriptions and
percentages of the students in each category are presented. The results show that
most student answer correctly representing 73.08%. Examples of category (a) are
shown in figure 4(a). They are able to analyze parallel and series circuits, and can
to draw simplified circuits by themselves. The highest source of misunderstanding
comes from the students’ misconception of current direction, with 19.23% of
students not considering the direction of current. Most students in this category do
not draw a simplified circuit and do not consider the direction of the power source.
This can be seen in Figure 4(b), where the students neglected the direction of the
battery. When the direction of current or the position of the battery is not
considered, the students incorrectly analyze the circuit. Interestingly, the students
in category (c) have a incorrect perception of parallel circuits. The student thinks
parallel circuits look similar to problem 3 and problem 4. This leads the student to
solve problem 2 incorrectly. The student think s that problem 2 is only a series
circuit. This misconception can be compared to Problem 3 in figure 4(c). The
student correctly understands parallel branch circuit but she incorrectly analyses
the next step, confusing a parallel circuit for a series circuit. For category (d), the
student uses the wrong formula. The student calculates the total resistance with the
formula Rtotal = 1/R1 + 1 /R2. For category (e), the student does not understand the
basics of circuits, so the specific reason for incorrect problem solving cannot be
explained.
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Figure 4(a) shows how students in category (a) solved the total resistance
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Figure 4(b) shows how students in category (b) solved the total resistance
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Figure 4(c) shows how students in category (c) solve the total resistance
TABLE II. MEAN PERCENTAGE OF FAVORABLE STUDENTS IN 6 DIMENSION OF STUDENT
EXPECTATION
Dimension of
expectation
Independence
Favorable response %
Correct answer
(category a)
Incorrect answer
(category b-e)
26.316
17.143
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Coherence
51.579
42.857
Concepts
23.685
19.049
Real-life
56.579
28.571
Math
28.948
19.050
Effort
47.368
28.571
Overall
41.486
29.833
In question 2, only 23.07% (6 students) correctly solved the problem.
Students who correctly solved question 2 correctly solved question 1 as well.
However, 68.42% (13 students) who correctly solved question 1 incorrectly solved
question 2. From observation, the way which students chose to solve question 2 are
Ohm’s law, Kirchhoff’s law (KCL & KVL) and a combination of Ohm’s law and
Kirchhoff’s law, while some students did not show how they solved the problem.
There are many causes of misunderstanding for question 2. For example, some
students incorrectly drew a simplified circuit. Some students who correctly drew a
simplified circuit were able to solve for total resistance and correctly solved can
solved for IA and VA, but incorrectly solved for the current and voltage for other
points (IB, IC, ID, VA, VB, VC, and VD). All students who incorrectly solved
question 1 could not solve question 2 as well, except for one student who
misunderstood the parallel circuit in question 1, but correctly solved for IA, IB, IC,
VA, VB, and VC, but incorrectly solved for point D. The circuit in question 2 is
quite complex, so it cannot be directly solved with Ohm’s law alone., and
Kirchhoff’s current law (KCL) and Kirchhoff’s voltage law (KVL) are required.
Most students tried to solve using Ohm’s law alone. Some students solved this
circuit with KCL and KVL alone, but were incorrect, because they could not
identify the voltage at each point, and could not analyze the current loops and
incorrectly solved for the currents. Therefore, the concepts of KCL and KVL are
emphasized in teaching, and students have to practice solving circuit which used
KCL and KVL. Table III shows that the percentage of students which correctly
answered in each point, and shows that that the solving for the current is more
difficult that solving for the voltage.
Finally, Table IV presents the mean percentage of favorable responses in 6
dimensions of expectations. The students are divided into 2 groups. The first group
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consists of students who could correctly solve the circuit, while the second group
consists of students who incorrectly solved it. Students in the first group for
question 2 have higher a favorable response percentage for most dimensions of
expectations than the second group of students. Moreover, ANOVA is used to
analyze the significant difference between the two groups (for correct and incorrect
answer) and 6 dimensions of expectations are shown in Table IV. Independence
(0.037), coherence (0.022), association with reality link (0.017), and math link
(0.013) are significant for the circuit solving. The significant difference between
overall expectation, the students who could solve the circuit and the students who
could not solve is 0.005. This shows that the students who have a higher favorable
response percentage solved the circuits correctly.
TABLE III. PERCENTAGE OF STUDENTS CORRECT ANSWER IN THE SECOND CIRCUIT
THE VALUE IN
CIRCUIT
PERCENTAGE OF
STUDENTS
CORRECT
ANSWER
THE VALUE IN
CIRCUIT
PERCENTAGE OF
STUDENTS
CORRECT
ANSWER
VA
100
IA
65.38
VB
88.46
IB
61.54
VC
80.77
IC
46.15
VD
30.77
ID
38.46
VE
80.77
IE
50
VF
80.77
IF
38.46
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Table IV. Mean percentage of favorable students in 6 dimension of student
expectation
Dimension
of
students expectation
Favorable response %
Sig
Correct answer
Incorrect answer
Independence
40.00
19.00
.037
Coherence
73.33
42.00
.022
Concepts
30.55
20.00
.187
Reality link
79.17
40.00
.017
Math link
44.45
20.83
.013
Effort
50.00
40.00
.443
overall
52.94
33.97
.005
Conclusions
From the results, this study shows that students who can solve the circuit problem,
they simplify circuit by themselves. We found that the misunderstanding about
solving total resistance is misconception of current direction, misconception of
parallel circuit and wrong formula. However, most students can solve correctly.
On the other hand, for complex circuit, we found that most student answer
incorrectly. KCL and KVL concept is difficulties for solving circuit for high
school level. Finally, the results shows the significant difference (<0.05) correlate
between the overall favorable scores and circuit solving result. Student who
attitude is same as expert can learn direct electric circuit better.
Acknowledgments
I would like to thank all the staffs of Engineering Science classroom (ESC) of
King Mongkut’s University of Technology Thonburi (KMUTT) of Thailand for
developing and organizing ESC curriculum. I also would like to thank Assoc. Prof
.Poj Tangamchit for his effort for enjoy direct electricity class and developing the
test. And I aslo would like to thank Mr. Pian Pawakapan and Miss Sukanyapat
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Dokkularb for many valuable discussion and suggestion to this study. Finally, I
would like to thank Mr. Samart Suanma for your support and love always.
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