Objectives (5 - 7 minutes)

• Main Objective: Introduce the concept of electrical power and how it is measured in electrical circuits. Students should understand that electrical power is the amount of energy that an electrical device consumes or produces per second.

• Secondary Objectives:

  1. Familiarize students with the units of measurement for electrical power, highlighting the watt (W) as the standard unit.

  2. Explain how to calculate electrical power in simple circuits, using the formula P = V x I, where P is power, V is voltage, and I is current.

  3. Demonstrate the difference between active and reactive power, explaining how each of them contributes to the total load in a circuit.

  4. Apply the concept of electrical power to everyday situations, such as calculating the power of an electrical appliance or understanding the value of an electricity bill.

Introduction (10 - 15 minutes)

• Review of previous content: The teacher should begin the lesson by reviewing the previous concepts that are fundamental to understanding the current topic. This includes a brief review of electricity, electric current, voltage, and resistance. It may be helpful to recall the basic formulas for these concepts and ask a few quick questions to assess students' understanding. (3 - 5 minutes)

• Problem situation: Present two problem situations to pique students' curiosity and attention:

  1. Imagine that you have two identical pieces of equipment, but one of them consumes more energy than the other. How can we measure and compare the amount of energy each of them consumes?

  2. In a city, one family's electricity bill is higher than another's, even though both have the same number of appliances. What could be causing this difference? (3 - 5 minutes)

• Contextualization: Explain the importance of studying electrical power, showing how this concept is applied in our daily lives. Examples may include calculating the wattage of electrical appliances to understand their energy consumption, the importance of electrical power in energy generation and distribution, and how it affects the value of the electricity bill. (2 - 3 minutes)

• Topic introduction: To gain students' attention, the teacher can share some curiosities or stories related to the topic. Some examples may include:

  1. The invention of the wattmeter by James Watt, which allowed the measurement of electrical power for the first time and was fundamental to the development of electrical engineering.

  2. The difference between active and reactive power, and how the lack of reactive power can cause problems in a power distribution network.

  3. The average power consumed by a 100W incandescent light bulb compared to a 10W LED bulb, highlighting the benefits of energy efficiency. (3 - 5 minutes)

Development (20 - 25 minutes)

• Activity 1 - "Measuring Power" (10 - 12 minutes)

  1. Scenario: The teacher divides the class into groups of 4-5 students and gives each group a set of electrical equipment (light bulbs of different wattages, fans, hair dryers, etc.), a wattmeter, and a multimeter.

  2. Challenge: Each group must select a piece of equipment, connect it to a source of electrical power, and measure its power with the wattmeter. Then, they should try to calculate the power of the equipment using the formula P = V x I, with the voltage (V) and current (I) read on the multimeter.

  3. Procedure: The teacher supervises the activity, ensuring that the students are handling the equipment correctly and recording the measured and calculated power values.

  4. Reflection: After the activity, the teacher leads a classroom discussion, where each group shares their findings and difficulties. The teacher should highlight the importance of direct power measurement and the accuracy of the formula P = V x I when used correctly.

• Activity 2 - "Power in Everyday Life" (10 - 12 minutes)

  1. Scenario: The teacher presents, on a slide or poster, a list of different electrical appliances and their power values.

  2. Challenge: Each group must select three appliances from the list and calculate how much energy they would consume in a month, considering that they work an average of 3 hours per day.

  3. Procedure: Students should use the formula P = V x I, considering the voltage of the electrical network (usually 110V or 220V) and the daily usage time of the appliance.

  4. Reflection: The teacher guides a discussion on the results obtained, questioning students about how the power values influence energy consumption and, consequently, the value of the electricity bill. The goal is to make students realize the importance of choosing low-power appliances to save energy.

• Activity 3 - "Power and Energy Efficiency" (5 - 7 minutes)

  1. Scenario: The teacher presents the following situation: an energy company is planning to replace all the light bulbs in a city with LED bulbs, which consume less energy than the current incandescent bulbs.

  2. Challenge: Students must calculate the difference in power and energy consumption between the two bulbs, considering that they will be used for 6 hours per day, for a month.

  3. Procedure: Students should use the formula P = V x I, considering the voltage of the electrical network (usually 110V or 220V) and the daily usage time of the bulb.

  4. Reflection: The teacher leads a discussion on the results, emphasizing the concept of energy efficiency and how choosing equipment with lower power can lead to significant energy savings on a large scale.

Feedback (8 - 10 minutes)

• Group Discussion (3 - 4 minutes)

  1. The teacher should gather all students in a large circle to promote a group discussion. Each group should briefly share their solutions or conclusions from the previous activities. The teacher should ensure that all groups have the opportunity to speak.

  2. During the discussion, the teacher can ask questions to deepen students' understanding of the topic. Some examples of questions may include:

     • "Why is the power of an electrical appliance important for calculating energy consumption?"
     • "How does power affect the value of the electricity bill?"
     • "Why is it important to consider energy efficiency when choosing an electrical appliance?"

• Connection to Theory (2 - 3 minutes)

  1. The teacher should then review the theoretical concepts presented in the Introduction of the lesson and connect these concepts to the practical activities carried out.

  2. The teacher can, for example, highlight how the formula P = V x I is used to calculate power in an electrical circuit and how this was applied in the activities.

  3. In addition, the teacher can reinforce the difference between active and reactive power, and how these concepts are applied in the generation and distribution of electrical energy.

• Individual Reflection (2 - 3 minutes)

  1. To conclude the lesson, the teacher should propose that students reflect individually on what they have learned. The teacher can ask questions such as:

     1. "What was the most important concept you learned today?"
     2. "What questions have not yet been answered?"

  2. Students should be encouraged to write down their answers and share them in the next class. This can help the teacher identify any misunderstandings or areas of confusion that need to be addressed in future lessons.

• Teacher Feedback (1 minute)

  1. To conclude the lesson, the teacher should provide brief feedback on the students' performance, praising their effort and participation and highlighting any strengths or areas for improvement that he or she observed during the lesson.

  2. The teacher should also reinforce the importance of the concept of electrical power for everyday life, recalling the practical examples discussed during the lesson.

At the end of this process, students should have a solid understanding of the concept of electrical power and be able to apply this knowledge to everyday situations.

Conclusion (5 - 7 minutes)

• Content Summary (2 - 3 minutes)

  1. The teacher should begin the Conclusion phase by recapping the main points covered during the lesson. This includes the definition of electrical power, the formula for its calculation (P = V x I), the difference between active and reactive power, and how power affects energy consumption and the value of the electricity bill.
  2. The teacher can do this in an interactive way, asking students to recall the concepts and explain them in their own words.

• Connection of Theory to Practice (1 - 2 minutes)

  1. Next, the teacher should highlight how the lesson connected theory and practice. This may include discussing how the formula P = V x I, which was presented as a theoretical formula, was applied in practice to measure the power of different electrical equipment.
  2. The teacher may also mention how the practical activities helped reinforce the theoretical concepts, and how the group discussion allowed students to see different applications of the concept of electrical power.

• Extra Materials (1 minute)

  1. The teacher should suggest some extra materials for students who want to delve deeper into electrical power. This could include YouTube videos that explain the concept in a visual way, physics websites that have interactive simulations on electrical power, or online exercises that students can do to practice calculating power.
  2. The teacher should remind students that these materials are optional, but they can be useful for reinforcing what was learned in class.

• Everyday Application (1 - 2 minutes)

  1. Finally, the teacher should emphasize the importance of the concept of electrical power for everyday life. This may include discussing how understanding electrical power can help save energy and reduce the electricity bill, or how electrical power is used in energy generation and distribution.
  2. The teacher can also encourage students to look for examples of electrical power in their own homes, such as checking the power of different appliances or calculating the energy consumption of an appliance they use frequently.

At the end of this phase, students should have a clear understanding of the concept of electrical power and its practical importance. They should also have an idea of how they can continue to learn about the subject and apply this knowledge in their daily lives.