Contextualization

Faraday's Laws

Faraday's laws are a set of fundamental principles that describe how electric current is generated by a magnetic field. It was the English scientist Michael Faraday who, in the 19th century, conducted experiments and published his findings that allowed the understanding and use of electricity as we know it today. His studies gave rise to two essential laws that bear his name: Faraday's first law, which deals with electromagnetic induction, and Faraday's second law, which deals with electrolysis.

The first law of Faraday tells us that whenever the magnetic flux through a region varies, a current is induced. This variation can occur for various reasons such as: changes in the magnetic field itself; changes in the area of the region; or changes in the angle between the magnetic field vector and the surface.

On the other hand, the second law of Faraday, which deals with electrolysis, states that the amount of substance produced in electrolysis is directly proportional to the amount of electricity passing through the solution. This law is essential for the industrial production of various substances such as aluminum, chlorine, among others.

Importance of Faraday's Laws

Faraday's laws brought a huge advancement to science and are applied in various contemporary technologies. From wirelessly charging smartphones to electromagnetic induction used in the operation of generators and electric motors, to the industrial production of metals by electrolysis. Whether by plugging in an appliance or using a rechargeable battery, we are benefiting from Faraday's discoveries. Studying Faraday's laws allows us to better understand the world around us and use this understanding to create new technologies.

To delve deeper into the study of Faraday's laws, we suggest the following resources:

• Khan Academy - Electrolysis
• Brasil Escola - Faraday's Laws
• Manual do Mundo - How to make a motor with a magnet (electromagnetism experiment)
• Book: General Chemistry - Raymond Chang.

Practical Activity: Faraday in Action!

Project Objective:

To enable students to understand Faraday's Laws and their application through a practical experience of electromagnetic induction and electrolysis.

Detailed Project Description:

The project is divided into two main parts: in the first part, students will work with Faraday's first law by conducting a practical experiment to understand electromagnetic induction. In the second part, they will explore Faraday's second law through a practical electrolysis experiment.

This activity is intended to be carried out by groups of 3 to 5 students, with a duration of approximately two to four hours per student, spread over a week.

Required Materials:

First part (electromagnetic induction):

• 1 coil of enameled copper wire;
• 1 magnet;
• 1 LED lamp;
• 1 multimeter (optional).

Second part (electrolysis):

• 1 power source (can be a battery);
• 2 graphite rods (can be obtained from common pencils);
• 1 glass cup;
• Water and table salt.

Detailed Step-by-Step:

First part (electromagnetic induction):

1. Wrap the enameled copper wire around a cylindrical object (such as a pen, for example) several times to form a coil.
2. Connect the ends of the wire to the LED lamp.
3. Bring the magnet close to and away from the coil and observe the LED lamp. It should light up when the magnet moves in relation to the coil, indicating that an electric current has been induced.
4. By using a multimeter, students can measure the intensity of the current and the voltage generated during the movement of the magnet and discuss it.

Second part (electrolysis):

1. Place water in the glass cup and add salt.
2. Connect one end of the graphite rods to the power source (battery) and place the other end inside the saline solution.
3. Observe the electrolysis process occurring and discuss it.

Project Delivery:

At the end of the project, students must write a document in the form of a report containing:

1. Introduction: In this section, the student must contextualize the theme, its relevance and application in the real world as well as the objective of this project.

2. Development: Here, the student must explain in detail the theory behind the central theme of the project (Faraday's Laws), describe the activity carried out, the methodology used, and finally present and discuss the results obtained.

3. Conclusion: In this section, the student must summarize the main points, explain the learnings obtained in the project, and draw conclusions about the experiment.

4. Bibliography: The student must indicate the sources that served as the basis for the project, such as books, internet sites, videos, etc.

This practical activity should allow students not only to understand Faraday's Laws but also to experience them, encouraging cooperation, effective communication, and time management.