Classroom experimentation – Arduino projects to teach electromagnetism

In this paper, we offer high school physics teachers valuable insights into the effective incorporation of Arduino-based classroom physics measurements for teaching electromagnetics. By engaging students in activities that involve measuring the conductance of liquids and exploring the magnetic field of a solenoid, starting from fundamental concepts and progressing to more complex tasks, we facilitate their journey toward a deeper, abstract understanding of the subject matter. These projects, centered on digital technology, encompass activities such as digital data collection, data analysis, and even functions plotting. These hands-on experiences enhance students’ technical skills, and also provide teachers with a powerful quantitative teaching method, allowing them to emphasize specific physical phenomena and their underlying theoretical principles. Consequently, these Arduino-based measurements play a pivotal role in fostering students’ competence development and improving their attitude towards learning physics.


Introduction
Rapid technological development, along with changes in the economy and in the labor market mean that education must adapt to new conditions and expectations.The development of new skills and competences is critical.In the labor market, skills suited for the 21 st century are increasingly required alongside subject matter expertise.Most companies are seeking employees who possess both digital skills (IT-focused hard skills) and soft skills such as creativity, critical thinking, problem-solving, and teamwork -interpersonal communication [1][2].
As a result, there is a need in education to complement traditional teaching methods with practiceoriented activities.Through these activities, students can acquire practical knowledge and competencies that contribute to successful adaptation to the 21 st century, including successful integration into the labor market.
Many national curricula [3][4] emphasize the incorporation of everyday knowledge and highlight the need to acquire practical, current information in physics education.
In this paper, we focus on practice-oriented physics teaching methods, which support the development of hard skills necessary for researchers, physicists and engineers, as well as of soft skills, e.g.problem-solving, teamwork, creativity, etc.

Practice-oriented physics education 2.1. Hand, heart and head -psychomotor learning processes
Teaching or learning?As teachers, our goal is to impart knowledge and apply techniques and methods that support effective learning.The teacher is the one who, based on the profile of the learner group, designs and monitors the learning process to achieve positive cognitive changes in students.The teacher imparts knowledge and assists in its retention, deepening, understanding, and application through various classroom activities.
However, learning is not limited to the cognitive realm.More than just the brain is involved in learning.It is important to mention the role of motor skills in learning as well.The body plays an active role in acquiring knowledge.For example, during movement or through touch, we gather information about our surroundings.The information obtained in this way is transmitted through neural connections.We also associate emotions with different experiences.Effective learning requires a connection to be made to the knowledge acquired [5][6][7].
So, in a physics class, engaging students in the work processes using action-oriented methods (e.g.having the students build an experimental setup and perform measurement tasks independently) can elicit emotions related to the task in them.This emotional content can help establish a connection to what they have learned.
According to Edgar Dale's learning pyramid (Figure 1) [8], people tend to remember only 20% of what they read and heard, and about 90% of what they did.If students do not only listen to a lecture about the subject matter but also discover it through their activities, the psychomotor processes this initiates ensures they will not only remember the information later but will also be able to utilize it.

Classroom measurements -Arduino-supported physics learning
One excellent way to enhance students' in-class participation is the application of classroom measurements.Classroom measurements are conducted in small groups, with students working independently on assigned tasks under teacher supervision, and actively engaging in the process of discovery.The students can learn how to design and build various experimental setups, apply methods to reduce measurement uncertainties, all while exploring a range of possibilities for data acquisition, data processing, and data evaluation.A well-designed classroom measurement, coordinated by the teacher but executed by the students, helps develop students' physical thinking and contributes to skill and competency development.We recommend using Arduino1 for student experimentation, as it significantly contributes to practice-oriented physics education.Arduino, along with attachable sensors, can be acquired at a reasonable cost, allowing for the creation of various experimental setups for any physics lab.The abundance of tools enables multiple student groups to conduct measurements simultaneously during a single class.

Arduino lesson plans.
In order for student measurements to be effective in terms of knowledge development, proper lesson planning is necessary.When designing Arduino-supported lessons, the authors rely on Bloom's taxonomy [9].We create worksheets for our students that contain a series of questions, guiding them from the basics through practice exercises to more complex, abstract tasks that require more thinking.By following this logical path, students progress through various levels of knowledge organization.Figure 2 shows our lesson plan model.

Arduino measurement projects -To teach electromagnetism
In this paper, we introduce two Arduino measurements with worksheets that we designed for our high school students in the topic of electromagnetism.

Investigation of the conductance of a specific liquid [10]
The measurements provide students with an opportunity to apply and enhance their existing understanding of concepts related to direct current, resistance, conductance, electric circuits (specifically resistors in series), and Ohm's law.Using the provided circuit diagram and program code, students were required to perform measurements to explore and assess the conductance of both tap water and saltwater.During two 45-minute-long physics lessons, the students completed the worksheet 2 provided to them.The sheet contains both theoretical and practical activities, from instruction throughout practice tasks towards the Arduino-measurement in which students investigate the relation between salt content and conductance, using their existing knowledge about voltage, current and resistance.Figure 3 shows the structure of the lessons.After a quick revision of theory, the students could move on to the experiments.First, we asked our students to carry out a warm-up experiment: to examine which liquids conduct electricity (of distilled water, tap water, salt water).The aim of the task was to bring activity-centered physics problems closer to the students and to provide them with an opportunity to experiment with easily accessible, tools found in the physics storeroom that students are well accustomed to.This involved constructing a simple experimental setup independently.
Executing the introductory experiment laid the necessary foundation for Arduino-based measurements.We organized our students into groups of 4, and their job was to use the listed equipment to determine the conductance of a glass of tap water (approx.200 ml) and examine the dependence of its conductance on salt content.The worksheet guided students through the process step by step.
1. Students build the circuit -They connect the glass of water in series with a known resistor (1 kΩ).They use an H-bridge 3 as a switch.The H-bridge continuously alternates the voltage polarity, thus preventing electrolysis (it has a square wave signal, and creates alternate current from direct current).The circuit and the experimental setup are shown in Figure 4.  .In a series circuit, the current passing through each component in the circuit is the same.
The conductance of the investigated liquid can be calculated as follows: 5. Students conduct systematic measurements.They repeatedly add salt to the water in 0.05-gram increments, then proceed with the steps described in points 2-4.
Here, we present the results of our students' measurements.Based on the data (Table 1) and the diagram (Figure 5), our students explain the phenomenon: qualitatively in elemental training, and quantitatively for advanced students.Initially, conductivity increases linearly with salt concentration.However, as they conduct further measurements, they observe that conductance is no longer a linear function of mass: the solution begins to saturate.

Conductance-salt mass
In order to differentiate students and support the progress of quicker, more capable learners, we prepared additional, optional tasks.For example, students can provide an order-of-magnitude estimation of the conductivity of the liquid and conduct a basic literature review on the topic.
In this paper, we presented a project designed for an advanced-level physics group.In general classes, it is recommended to avoid calculations and derivations, and instead focus only on data collection, data processing, and analysis.To this end, the code has been modified.With the new code 4 , the conductance values are directly displayed.

Investigation of the magnetic field of a solenoid
Teaching the topic of the magnetic fields of current-carrying conductors presents numerous challenges for physics teachers.Traditional demonstration equipment assembly can be difficult and demands high precision.According to our experience, it can happen that teachers teach students formulas that describe magnetic fields without investigating it with measurements.To give these formulas meaning, we designed an experimental setup using small, easily obtainable components that allows students to construct it themselves.This setup enables a thorough study of the phenomenon (the magnetic field of a coil) and supports understanding of the topic.
Students worked in groups of 4 and conducted measurements supported by a worksheet5 , which it guided students through the process step by step.3.Then, the students also conduct some quantitative research.They put the sensor into the coil (in the center), then they continuously vary the voltage from zero, measuring the magnetic field induction value characteristic to the coil at different current intensities, and describe and evaluate the changes.
Table 2 shows measurement data and Figure 7 shows students' data analysis.The data are represented graphically.Through interpreting the graph, students demonstrate that magnetic induction is directly proportional to the current intensity.
For more capable students, we also prepared with an additional, optional activity.In this task, students determined the magnetic field induction as a function of distance at a constant current intensity.(Center of the coil:  = 0 , maximum distance:  = 10 ).
In both tasks, we expected students to describe their observations based on digitally recorded data.The graphical representation of the data made the relationship between the investigated quantities visible.Data collection, analysis, evaluation, and explaining the phenomenon go beyond basic knowledge.Therefore, the tasks we provided do not only develop cognitive skills, but also facilitate the integration of what students have learned, and the development of higher levels of understanding.

Students' opinion of Arduino measurements [11]
As a conclusion to the projects, we were curious about the students' attitudes towards Arduino-supported physics lessons.We had our students fill out a questionnaire in which they indicated what they liked and disliked about Arduino-based measurement tasks.Additionally, they rated on a 6-point Likert scale Magnetic field induction -current intensity how much they believed Arduino-supported student measurements contributed to the development of their certain competencies.Table 3 and Figure 8 contain students' answers to the questions.

What I like about Arduino-measurements
What I dislike about Arduino-measurement • The opportunity to use a modern device.
• The opportunity to get acquainted with modern measurement techniques.• They provide practical knowledge.
• They connect theory and practice.
• We can work at our own pace.
• The lessons are conducted in a positive atmosphere.• We can think about physics independently, we have the opportunity to get involved in our learning.
• A 45-minute-long lesson is not long enough to thoroughly delve into the tasks.• There may be some students in the groups who do not contribute to the task.• Sometimes we encounter problems that we have to solve (e.g.typos in the code).In our students' opinion, the Arduino-based measurements support the development of various competencies, especially setup design, data analysis and evaluation, and they help students with developing a theoretical model.The students also articulated the practical nature of Arduino-supported activities.The students believe that by completing the tasks, they acquire practical knowledge.A less attractive aspect of the measurement is that it sometimes spans multiple class periods, and the 45 minutes available in a single lesson are insufficient for proper immersion.Occasionally, students encounter challenges that they need to resolve in order to progress.The flip side of a potential benefit can also be a drawback: group work fosters a positive atmosphere, but at times, one member of the group may contribute less, which can be frustrating for the other students.

Conclusion
In our study, we presented two easily implementable classroom measurements linked to the topic of electromagnetism.The aim of the project is to encourage students to participate actively in physics classes and to engage them in their own learning processes.The measurements also enable students to describe various problems qualitatively and quantitatively.Classroom measurements supported by Arduino provide students with the opportunity to develop skills essential for success in the 21 st century.The project offers insight into scientific research and supports the acquisition of current, practical knowledge.The study introduced a possible way to investigate the conductivity of liquids and examination of the magnetic field of a coil using a simple and easily operable measurement setup.The purpose of the measurements is to provide insight into physical phenomena, enhance physical thinking, and develop research and engineering competencies.Additionally, students interested in programming can become involved in further improving the code.Furthermore, Arduino measurements are popular among students, which can contribute to the development of their attitude towards the subject, as well.The materials provided can be assembled at different levels of complexity, and offer valuable assistance to practicing physics teachers in both elementary and advanced-level education.
Watching a video, demonstration Discuss something -Design something Giving a presentation and write a plan DOING: modeling/doing the real thing E.g.: classroom measurement 10 % of what you read 20 % of what you hear You remember….30 % of what you see 50 % of what you see & hear 90 % of what you do

Figure 2 .
Figure 2.An example lesson plan model of Arduino-supported physics lessons.

Figure 3 .
Figure 3. Structure of lessons dealing with electrical conductance.

Figure 4 .
Figure 4.The experimental setup.Water is connected in series with a known resistor.Arduino operates as an intelligent voltmeter; power is supplied to it by the laptop.An H-bridge is used as a polarity switch.The aluminum terminals of Arduino wires serve as electrodes.

3
H-bridge: http://www.handsontec.com/dataspecs/L298N%20Motor%20Driver.pdfa: 17 September 2023) • Revision of theory and practice theoretical tasks • Homework: Matura exam activities and some practical physics Instruction • Beginner-level experiment • Arduino-measurement, data gathering and bonus tasks Measurement 26th International Conference on Multimedia in Physics Teaching and Learning Journal of Physics: Conference Series 2693 (2024) 012015 The voltage of Arduino power supply is 5V.Students determine U1 based on the formulas of series connection:  1 = 5  − . 4. Students calculate the current intensity (I = I1) and determine the conductance of tap water.The current flowing through the known resistor can be determined as follows:  =

Figure 5 .
Figure 5. Results -Data analysis.Conductance-salt content of tap water diagram.

1 .
Students build the circuit using the listed equipment (Solenoid:  = 1,000,  = 8 ; Voltage source: 0 − 20 ; ammeter).They use an Arduino-controlled Hall-sensor for conducting the experiments.The circuit and the experimental setup can be seen in Figures 6.a and 6.b.

2 .
Students begin to investigate the field of the current-carrying coil.They upload the code 6 to the Arduino with which they can output the value of magnetic field induction (B).They set the current to a constant value and observe changes in B-values by moving the Hall-sensor from the middle of the coil to the end.They qualitatively explain the changes.26th International Conference on Multimedia in Physics Teaching and Learning Journal of Physics: Conference Series 2693 (2024) 012015 IOP Publishing doi:10.1088/1742-6596/2693/1/0120157

Figure 7 .
Figure 7. Magnetic field induction as a function of current intensity.

Figure 8 .
Figure 8. Students' opinion of the role of Arduino in competence development.Answers were provided on a 6-point Likert scale.The numbers in the center indicate the average score students give to each competence.Numbers in brackets: standard deviation.

Table 1 .
Measured and calculated data.

Table 2 .
Measurement data.Magnetic field induction as a function of current intensity.