Contextualization

Electricity is one of the fundamental forces of nature, it is everywhere around us and has applications that range from everyday life to the most sophisticated advances in high technology. One of the key components that allow us to control and direct this force are resistors. In your computer, in your cell phone, in your microwave, in basically every electronic device you use, there are resistors silently doing their job.

Resistors, as the name suggests, resist the passage of electricity, thus being able to decrease the electric current in an electric circuit. Resistors can be connected in different ways, two of them being the series connection and the parallel connection. In this project, we will focus on the series connection. We will understand what it is, how it works, how to calculate the total resistance, and what happens to the current and voltage in a series resistor circuit.

Introduction

In a series resistor circuit, the resistors are connected one after the other, as if they were links in a chain. This means that the current (the amount of electrons passing through a point in the circuit per second) that goes through all the resistors is the same. The voltage (or potential difference) can vary from resistor to resistor, depending on each one's resistance.

The total resistance of a series resistor circuit is the sum of the resistances of each resistor. This happens because resistance is a measure of how difficult it is for the current to pass through a material, and the more material the current has to pass through (that is, the more resistors in series), the harder it will be for the current to pass.

Finally, it is worth mentioning that series resistors have a very interesting characteristic: if any of them fails (that is, if its resistance goes to infinity), the entire circuit current is interrupted. This has important practical applications and is also a point that must be understood to fully comprehend the behavior of series resistors.

As a suggestion for further reading and to delve deeper into the topic, we recommend the following resources:

• Resistors in Series and Parallel - Brasil Escola
• Series and Parallel Resistor Circuits - Mundo Educação
• Video Lesson - Resistors in Series - Khan Academy

Practical Activity

Activity Title: "The Resistance Chain"

Project Objective

1. Understand the theory of the behavior of resistors in series.
2. Conduct a practical experiment to observe the behavior of resistors in series.
3. Develop communication and teamwork skills.
4. Develop skills in analysis, prediction, and problem-solving.

Detailed Project Description

1. Form groups of 3 to 5 students. Each group will be responsible for conducting the practical experiment and writing a detailed report on the results obtained and conclusions.

2. Each group will build and analyze a series resistor system. They should calculate the total resistance, measure the current and voltage in each resistor, and compare the results with theoretical predictions.

3. Next, each group should propose and make changes to their system and predict the consequences of these changes, comparing their predictions with the observed results.

4. Finally, each group should reflect on the implications of their results for practical everyday applications and for sustainability.

Required Materials

1. Three resistors with different resistances
2. A power source (battery)
3. A multimeter
4. Conductor wires
5. Connectors

Detailed Step-by-Step for Activity Execution

1. First, students should study in detail the theory of resistors in series, their characteristics, and associated mathematical expressions.

2. Next, students will use the resistors, power source, and conductor wires to assemble the series circuit.

3. Using the multimeter, students should measure the total circuit current and the voltage across each resistor.

4. Students should then calculate the total circuit resistance using the measurements obtained and compare this value with the sum of the resistances of the individual resistors.

5. After that, students should alter the circuit, changing the order of the resistors, adding more resistors, or changing the power source, for example. They should make predictions about how these changes will affect the total current and the voltage across each resistor.

6. New measurements should be taken and compared with the predictions. Discrepancies should be analyzed and explained.

7. Finally, students should reflect on the impact of practical applications of the concepts learned in terms of efficiency and sustainability.

Project Deliverables

1. Each group must submit a report, which should include an introduction to the topic, the development of the practical work, the conclusions drawn, and the bibliography used. The report should contain details about the theory studied, the experiment conducted, and the analysis of the results. It should also include a photographic or video record of the practical experiment.

2. The report's development section should describe the steps of the experiment, the measurements taken, and the calculations performed. It should also include the predictions made and the comparison between the predictions and the results obtained.

3. In the conclusions section, students should summarize the main points of the work, present the learnings obtained, and the conclusions drawn about the project. It should also include a reflection on the implications of the results for practical applications and sustainability.

4. Finally, the bibliography used for theoretical grounding should be properly referenced.