Context

Introduction

A magnetic field is, in a simplified way, a region influenced by magnetic forces that act on magnets and magnetizable bodies. Each magnetized body creates a magnetic field around itself. By immersing a magnetizable object in this field, it will be subject to magnetic forces.

The magnetic field is not a physical object, it is a way to map the magnetic influence in a region of space. This field is the means by which magnetic forces are transmitted. The magnetic field is both an influence created by magnets and electric currents, and an influence that acts on magnets and electric currents.

The direction and magnitude of the magnetic field are determined by the direction and magnitude of the force it will exert on a magnetic north pole placed at that location. Thus, when we talk about the direction of a magnetic field, we are referring to the direction of the force that this field would exert on a north pole placed at that location.

Magnetic Field and its Applications in the Real World

The study of the magnetic field is vital because the magnetic field is present in our daily lives in various ways. For example, it is crucial for the operation of many electrical devices such as motors and generators.

The Earth's magnetic field protects our planet from the charged particles emitted by the Sun. Without this magnetic field, life as we know it would not be possible. In addition, magnetic fields are used in various technological applications, such as in computer hard drives, credit cards, maglev trains (which levitate due to magnetism), and many others.

As electric currents create magnetic fields and magnetic fields can induce electric currents, the study of the magnetic field helps us understand the interconnection between electricity and magnetism, a field known as electromagnetism, which is the basis for modern technology.

Practical Activity

Activity Title: Identification and Creation of Magnetic Fields

Project Objective

The objective of this project is for students to experiment practically with the theory studied about magnetic fields, verifying their properties. They will identify the magnetic field of a common magnet and create a magnetic field using electric current.

This project should be carried out by groups of 3 to 5 students, and the total project duration is estimated to be 2 to 4 hours, dividing the tasks among the group members.

Detailed Project Description

Students will carry out two practical activities. In the first one, they will visually demonstrate the magnetic field of a common magnet using iron filings. In the second one, they will create a magnetic field around a wound copper wire, in other words, they will create an electromagnet.

Required Materials

1. Magnets.
2. Iron filings.
3. Paper.
4. Enamel-coated copper wire.
5. Batteries.
6. Paper clips or other small metal pieces.

Detailed Step-by-Step

Step 1: Visualization of a Magnetic Field

1. Place a piece of white paper over the magnet.
2. Gently spread the iron filings over the paper.
3. Observe how the iron filings align along the invisible lines of the magnetic field.
4. Record your observations, sketching the pattern formed by the iron filings and noting your findings.

Step 2: Creation of a Magnetic Field (Electromagnet)

1. Wind the enamel-coated copper wire around a long, cylindrical object (such as a pen or a nail) several times to form a coil. Leave some loose wire ends at each end.
2. Connect the loose wire ends to the battery, creating a circuit.
3. Try to pick up small metal objects (such as paper clips) with your electromagnet.
4. Record your observations, sketch your electromagnet, and note all findings.

After completing the practical activities, each group should prepare a project report.

Project Deliverables

The group must submit a written report with four parts: Introduction, Development, Conclusions, and Bibliography used.

Introduction: It should contain the contextualization of the topic, the relevance and applications of the magnetic field in the real world, as well as the project's objective.

Development: In this section, the group must explain in detail the activities carried out. The theory behind the magnetic field and how each experiment was conducted should be explained. In addition, images or sketches of the activities performed and the results obtained should be included.

Conclusions: The group must summarize the main points of the report, conclude on their findings and experiences, and share what they learned from carrying out the project.

Bibliography: The group must list all sources of information used to develop the project, including books, websites, videos, among others.

Finally, students should reflect in their report on the socio-emotional skills developed during the project, such as time management, communication, problem-solving, creative thinking, and proactivity.