Contextualization
Magnetic field is a vector magnitude, that is, it has direction, sense, and magnitude. It acts on moving charged particles, being generated by electric currents or magnets. The study of the magnetic field, as well as electricity, is of great importance for modern life, being applied in numerous technologies such as electric motors, generators, loudspeakers, among others.
A very interesting and useful way to generate a magnetic field is by using a coil of wire, also known as a solenoid. The magnetic field inside a solenoid is uniform and its determination is based on Ampere's law. The solenoid is widely used in industry and science, such as in electromagnets, transformers, electric motors, and even in Magnetic Resonance Imaging, which is one of the most powerful medical diagnostic tools.
Through this project, you will have the chance not only to understand in practice the magnetic field produced by a solenoid but also to become familiar with fundamental concepts of electromagnetism. In addition, you will develop important socio-emotional skills such as teamwork, time management, problem-solving, and proactivity.
To help you get started and learn more about the topic, I suggest the following study sources:
- Book "Physics for Scientists and Engineers - Volume 2" by Paul A. Tipler and Gene Mosca.
- Website "Brasil Escola" (article available at: https://brasilescola.uol.com.br/fisica/campo-magnetico-solenoide.htm) which provides a simple and didactic explanation about the formation of a magnetic field in a solenoid.
- YouTube channel "Física Universitária" which has explanatory videos on various physics topics, including the magnetic field generated by a solenoid.
Practical Activity
Activity Title: Construction and Analysis of a Solenoid
Project Objective
The project aims to build a simple solenoid and analyze the magnetic field generated by it. Students will learn concepts such as magnetic field, field strength, direction and sense, besides delving into the working principle of a solenoid. Finally, they will better understand the relationship between electricity and magnetism.
Detailed Project Description
Students, in groups of 3 to 5 people, will build a solenoid using common materials and measure the magnetic field strength generated by it. With these measurements, students will be able to compare with the theoretical values obtained by the equations that describe the magnetic field of a solenoid.
Required Materials
- 1 roll of enameled copper wire
- 1 strip of cardboard long enough to wrap the wire and form the solenoid
- 1 voltage source
- 1 multimeter with an option to measure magnetic field
- 1 ruler
- Electrical tape
Detailed step-by-step instructions for carrying out the activity
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Wind the enameled copper wire onto the cardboard, forming several turns very close to each other. Make sure that the turns are all in the same direction. The number of turns is an important parameter, so count how many you made. The result will be your solenoid.
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Connect the solenoid to the voltage source. To do this, remove a small amount of enamel from the ends of the copper wire using sandpaper, for example, so that the electric current can pass through.
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Set the multimeter to the option to measure magnetic field.
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Insert the multimeter probe inside the solenoid and note the magnetic field strength.
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Repeat measurements for different current values provided by the voltage source. Always take note of the values.
Project Deliverables
The group must submit a report containing:
1. Introduction
Students should introduce the topic, explaining what a solenoid is and why it is important to study it. They should also describe the purpose of the project and how it applies in the real world.
2. Development
In this section, the group should describe the theory behind the magnetic field of a solenoid, use Ampere's Law to demonstrate how to theoretically calculate the magnetic field strength, and detail the experimental procedure they performed, including the methodology, materials used, and results obtained.
3. Conclusion
At this point, students should summarize the project, highlight the learning outcomes and conclusions drawn, relating the experimental results to the theory presented.
4. Bibliography
The group should indicate the sources on which they based their work. They should include any books, articles, or websites they have consulted.
The report should complement the practical activities carried out, explaining the theory behind the magnetic field of a solenoid and how it can be quantified. It should also detail the processes used in the construction of the solenoid and measurement of the magnetic field, the results obtained, and the analysis made based on these results.