Contextualization

The magnetic field generated by a coil is one of the fundamental topics in Physics, which is part of the study of electromagnetism and is crucial for our understanding of how many of the devices and technologies we use daily work. But before we delve into its applications, let's better understand this concept.

Every electric current generates a magnetic field around it. When we pass this current through a curved conductor wire, forming a coil, this magnetic field concentrates inside this coil and creates an effect similar to that of a magnet, with north and south magnetic poles. The generated magnetic field can be increased or decreased by varying the intensity of the electric current along the coil wire.

By stacking several of these coils, we create what we call a solenoid. The magnetic field generated by a solenoid is strong inside the solenoid itself and weak outside of it. The direction of the magnetic field is related to the direction of the current, and this can be determined by the right-hand rule.

Now, why is this important? In the real world, the magnetic field generated by a coil and by solenoids has vast applications. These concepts are used, for example, in power generators, electric motors, transformers, magnetic resonance imaging devices, speakers, among others. This everyday presence highlights the importance of understanding this concept for the comprehension of the world and its technologies.

It also relates to other fields of knowledge, such as mathematics in the analysis of the behavior of magnetic fields and in problem-solving, chemistry in the analysis of the effects of magnetic fields at the atomic level, and computer science in the use of magnetic fields for data storage.

To delve deeper into the study of the magnetic field generated by a coil, it is suggested to use the following resources: The book "Physics for Scientists and Engineers - Vol. 3: Electromagnetism" available in many libraries, the website "Brasil Escola" (https://www.brasilescola.uol.com.br/fisica/campo-magnetico-uma-espira.htm), which contains detailed explanations and practical examples on the subject. For a visual approach, the YouTube channel "Física Universitária" (https://www.youtube.com/watch?v=Z8Y3Pmw9a0g) offers an explanation of the magnetic field generated by a coil through the use of animations.

Practical Activity: "Building and Exploring the Magnetic Field of a Coil"

Project Objective

The objective of this project is to provide a practical learning experience on the magnetic field generated by a coil through the construction of a simple model. The activity aims to explore the theoretical concepts experimentally, allowing students to visualize and demonstrate the behavior of the magnetic field.

Detailed Project Description

This project will be carried out by groups of 3 to 5 students over a period of at least 12 hours per student (thus establishing a workload of at least 36 to 60 hours per group), distributed over three weeks. It is recommended that students divide their time between research, planning, model construction, conducting experiments, analyzing results, and preparing the final report.

This interdisciplinary project connects Physics with Mathematics in the analysis and interpretation of measurements and results, as well as stimulates competencies such as teamwork, time management, communication, and critical thinking.

Required Materials

1. Copper wire (approximately 5 meters)
2. A 9V battery
3. Ammeter and voltmeter
4. Sewing needle
5. Paper
6. Compass
7. Ruler
8. Pencil or pen

Detailed Step-by-Step

1. Each team should research how to calculate the magnetic field produced by a coil of electric current. With this research, students should be able to predict the behavior of the magnetic field, such as its direction and intensity, based on the variables involved: current intensity and coil radius.

2. The students should then build the coil using the copper wire, shaping it to create a coil of known radius (for example, the sewing needle can be used as a mold).

3. With the coil ready, place it flat on a sheet of paper and trace the outline of the coil.

4. Connect the coil to the 9V battery and record the current in the circuit with the help of the ammeter.

5. Use the compass to observe the behavior of the magnetic field generated by the coil. Draw on the paper the direction indicated by the compass at various points around the coil.

6. Repeat steps 4 and 5 for different current intensities (the current can be varied by changing the battery configuration or adding resistors to the circuit).

7. Analyze the drawings and compare them with the theoretical predictions.

Project Deliverables and Document Preparation

At the end of the activity, each team must deliver:

1. Logbook: should record all stages of the project, from the initial planning, team discussions, coil construction, experiment execution, to the final analysis of the results. This document will be useful for the preparation of the final report.

2. Final Report: should be written in the format of a scientific report, containing:

   • Introduction: contextualize the topic, its relevance and real-world application, and the objective of this project.

   • Development: explain the theory behind the magnetic field of a coil, describe in detail the activity carried out, indicate the methodology used, and present and discuss the results obtained.

   • Conclusion: summarize the main points of the work, explain what was learned, and draw conclusions about the project.

   • Bibliography: indicate the sources used for the project.

The entire project must be documented, from the initial discussions to the final analysis of the results. This documentation will compose the 'Logbook', which will serve as the basis for writing the final report.

Remember that this activity will not only assess students' knowledge of the magnetic field generated by a coil, but also their teamwork skills, problem-solving abilities, critical thinking, time management, and communication.