Objectives (5 - 7 minutes)

1. Understand the concept of electrical resistance and how it relates to the flow of electric current.
2. Learn how to calculate the equivalent resistance in circuits with series and parallel association.
3. Develop skills to solve practical problems involving the association of resistors in electrical circuits.

Secondary objectives:

• Recognize the components of an electrical circuit and their function.
• Apply Ohm's and Kirchhoff's laws to solve problems involving resistors.
• Develop critical thinking and problem-solving skills through the study of electrical circuits.

Introduction (10 - 15 minutes)

1. Review of previous concepts: The teacher begins the class by reviewing the concepts of electric current, voltage, and resistance. He can do this through a quick theoretical review, questioning students to check if they remember the concepts and how they relate. (3 - 5 minutes)

2. Problem situation: The teacher presents two problem situations to arouse students' interest:

   • Situation 1: Imagine that you have a flashlight with two batteries in series. If one of the batteries fails, will the flashlight still work? Why?

   • Situation 2: If you have two lamps and connect them in parallel to a battery, will they shine more or less than if they were connected in series? Why? (3 - 5 minutes)

3. Contextualization: The teacher explains to the students that the study of the association of resistors is essential for understanding how many electronic devices work. He can give examples of how resistors are used in computer circuits, televisions, cell phones, among others. The teacher can also mention that the energy efficiency of many devices depends on the correct use of the association of resistors. (2 - 3 minutes)

4. Presentation of the topic: The teacher introduces the topic of "Association of Resistors" explaining that, in many cases, it is necessary to combine resistors to obtain the desired resistance in a circuit. He can mention that this is done in circuits of electronic devices, lamps, motors, among others. The teacher can also show images or drawings of resistors and explain how the resistance of each one is measured. (2 - 3 minutes)

Development (20 - 25 minutes)

1. Activity "Path of Resistance" (10 - 12 minutes)

   • The teacher divides the class into groups of up to five students and gives each group a circuit assembly kit (which can be made with wires, batteries, lamps, and resistors of different resistances).
   • Each kit includes a diagram of a circuit and the necessary components to assemble it.
   • The teacher explains that students should assemble the circuit according to the diagram and then measure the current that passes through it using an ammeter and the voltage in different parts of the circuit using a voltmeter.
   • Students should note the readings and then use Ohm's law to calculate the resistance of the segment of the circuit they are measuring (V = I * R, where V is the voltage, I is the current, and R is the resistance).
   • After the calculation, students should compare their measurements with the actual resistances of the resistors used in the circuit and discuss possible sources of error.
   • This activity will allow students to experience the measurement of resistance in a circuit and see how the resistances add up in a series association.

2. Activity "The Resistance of the Group" (10 - 12 minutes)

   • In this activity, students continue to work in groups and are now challenged to design and assemble a circuit that has a specific resistance.
   • The teacher provides students with a list of resistors with different resistances and a resistance target for the circuit (for example, 10 ohms).
   • Students should select the appropriate resistors and assemble the circuit so that the total resistance is equal to the target.
   • After assembly, students should measure the resistance of the circuit and compare it to the target. If the resistance is not desired, students should adjust the circuit by adding or removing resistors until they reach the desired resistance.
   • This activity will allow students to experience the combination of resistors in a parallel association and see how the total resistance is affected.

3. Group Discussion (5 - 6 minutes)

   • After completing the activities, the teacher leads a group discussion, in which each group shares its findings and difficulties encountered during the activities.
   • The teacher should guide the discussion, asking questions to deepen students' understanding of the association of resistors.
   • The teacher should also clarify any misconceptions that may arise and reinforce the key concepts of the lesson.

Return (8 - 10 minutes)

1. Group Discussion (3 - 4 minutes)

   • The teacher leads a group discussion where each team shares their solutions or conclusions from the activities "Path of Resistance" and "The Resistance of the Group".
   • The teacher can ask a representative from each group to briefly present their findings, results, and thought processes.
   • During the presentations, the teacher should encourage the participation of all students, asking questions to check for understanding and promote meaningful discussion.

2. Connection to Theory (2 - 3 minutes)

   • The teacher then connects the activities to the theory presented in the Introduction to the lesson.
   • He can do this by explaining how the activities demonstrated the practical application of the concepts of resistor association and how the calculations made by the students are a direct expression of Ohm's and Kirchhoff's laws.
   • The teacher can also reinforce the importance of the concepts learned, showing examples of how they are applied in the real world, for example, in electrical engineering, electronics, and energy saving.

3. Individual Reflection (2 - 3 minutes)

   • The teacher asks the students to reflect individually on what they learned in class.
   • He can do this through guiding questions, such as: "What was the most important concept you learned today?" and "What questions have not yet been answered?" .
   • Students have one minute to think and then are invited to share their answers with the class.
   • The teacher should listen carefully to students' answers, clarify any misconceptions, and encourage discussion.

4. Feedback and Closing (1 minute)

   • Finally, the teacher thanks the students for their participation, gives positive feedback on the teamwork and collaboration shown during the class and encourages the students to continue studying the subject at home.
   • He can suggest some additional activities or readings to deepen students' understanding of the resistor association.
   • The teacher reinforces that understanding this topic is fundamental for success in future physics classes and practical activities.

Conclusion (5 - 7 minutes)

1. Summary of Contents (2 - 3 minutes)

   • The teacher summarizes the main points covered during the class, reinforcing the concept of electrical resistance, the difference between series and parallel association, and the application of Ohm's and Kirchhoff's laws in solving problems with resistors.
   • He can do this through a slide or panel presentation, where he highlights the key concepts and important formulas.
   • The teacher can also make a brief summary of the solutions or conclusions found by the students during the practical activities.

2. Connection between Theory, Practice, and Applications (1 - 2 minutes)

   • The teacher emphasizes how the lesson connected the theory of resistors with practice, through the activities "Path of Resistance" and "The Resistance of the Group".
   • He can mention how the experiments carried out by the students illustrated the theoretical concepts of resistor association and how the resolution of practical problems helped to reinforce the students' understanding of the subject.
   • The teacher can also discuss some real-world applications of resistor association, such as the operation of electronic devices and energy saving.

3. Supplementary Materials (1 minute)

   • The teacher suggests additional study materials for students who want to deepen their knowledge of resistor association.
   • He can recommend books, videos, physics websites, and online exercises that approach the topic in a clear and didactic way.
   • In addition, the teacher can make available the circuit diagrams used in the practical activities, so that students can review them at home.

4. Importance of the Topic (1 minute)

   • Finally, the teacher emphasizes the importance of the topic for students' daily lives.
   • He can mention how understanding the association of resistors is essential for understanding many electronic devices that we use daily, and how the ability to calculate the equivalent resistance in a circuit can be useful in various practical situations.
   • The teacher can also emphasize that mastering this topic is crucial for success in future physics classes and activities, and that continuous practice is the key to full and effective understanding of the subject.