Lesson plan of Electricity: Electric Current

Objectives (5 - 10 minutes)

1. Understand the concept of electric current and the factors that influence it:

   • Students should be able to explain what electric current is and how it is formed.
   • They must understand that electric current is the movement of electric charges and that the intensity of the current depends on the amount of charge that passes through a point in a given time.

2. Differentiate between direct current and alternating current:

   • Students must be able to identify the distinct characteristics of each type of current.
   • They must understand that direct current is unidirectional, while alternating current changes direction periodically.

3. Understand the concept of electrical resistance and the factors that affect it:

   • Students must be able to define what electrical resistance is and how it manifests in a circuit.
   • They must understand that resistance depends on the material of the conductor, the length of the conductor, and its cross-sectional area.

Secondary objectives:

• Apply the concepts learned to solve practical problems:
  • Students must be able to use the formulas and concepts learned to solve problems related to electric current and electrical resistance.

Introduction (10 - 15 minutes)

1. Review of previous concepts:

   • The teacher begins the class by reviewing the concepts of electricity, conductors and insulators, electric voltage, and electric potential. These are fundamental to understanding the new topic, electric current. (3 - 5 minutes)

2. Problem situations to arouse interest:

   • The teacher proposes two problem situations to start the discussion. First, he asks students why the bulb of a flashlight shines brighter when the battery is new. Then, he asks students to think about why a long, thin wire heats more than a short, thick wire when an electric current passes through it. (5 - 7 minutes)

3. Contextualization of the importance of the topic:

   • The teacher contextualizes the importance of the topic, explaining that electric current is what allows all the electronic devices that we use daily to function, from light bulbs and electronic devices to public lighting and transportation systems. (2 - 3 minutes)

4. Presentation of the topic with curiosities:

   • The teacher introduces the topic of electric current with two curiosities. First, he mentions that the concept of electric current was discovered by chance by Luigi Galvani in the 18th century, when he realized that the legs of a frog moved when a piece of metal was placed in contact with its muscle and a nerve. Second, he shares that one of humanity's greatest inventions, the incandescent lamp, was only possible thanks to the study of electric current and electrical resistance by Thomas Edison. (3 - 5 minutes)

Development (20 - 25 minutes)

1. Electric Current Theory (5 - 7 minutes):

   • The teacher begins the explanation of the concept of electric current, highlighting that it is the movement of electric charges (electrons) in a conductor.
   • He should emphasize that electric current flows from the negative pole to the positive pole of a voltage source (such as a battery or outlet), although the charge (electrons) flows in the opposite direction.
   • To help visualize, the teacher can use the analogy of a queue of people passing a ball: the ball is the electric charge and the queue is the conductor.
   • The teacher should introduce the unit of measurement of electric current, the ampere (A), and explain that 1 ampere corresponds to 1 coulomb of charge passing through a point in 1 second.

2. Direct and Alternating Current Theory (5 - 7 minutes):

   • The teacher should now explain the difference between direct current and alternating current.
   • He should emphasize that in direct current, the direction of electron flow is constant, while in alternating current, the direction of electron flow changes periodically.
   • The teacher can use a diagram with arrows to illustrate the difference between the two.
   • He should mention that most electronic devices in our homes, such as light bulbs and televisions, operate on direct current, but the electricity that comes from outlets is alternating current.
   • The teacher can explain that alternating current is used in the transmission of electricity over long distances, as it is more efficient in this type of transmission.

3. Electrical Resistance Theory (5 - 7 minutes):

   • The teacher should introduce the concept of electrical resistance, explaining that it is the difficulty that electrons encounter when moving in a conductor.
   • He should emphasize that resistance depends on the material of the conductor, the length of the conductor, and its cross-sectional area.
   • The teacher should present the unit of resistance, the ohm (Ω), and explain that 1 ohm corresponds to 1 volt of voltage applied to a conductor producing a current of 1 ampere.

4. Examples and Applications (5 - 7 minutes):

   • The teacher should now present examples and applications of the concepts explained.
   • He can show how to calculate the resistance of a conductor using the formula R = ρ (resistivity) x L (length) / A (cross-sectional area).
   • The teacher can also show how to use Ohm's law (V = R x I, where V is voltage, R is resistance, and I is current) to solve problems involving current, voltage, and resistance.
   • To illustrate the practical application, the teacher can use everyday examples, such as choosing the wire to be used in an electrical installation (depending on the current that will pass through it and the distance it will travel) and choosing a light bulb for a luminaire (depending on the voltage of the network and the current that will pass through it).

Return (10 - 15 minutes)

1. Review of Concepts (3 - 5 minutes):

   • The teacher begins the review stage by asking students to summarize, in their own words, the concepts of electric current, direct current, alternating current, and electrical resistance.
   • He can select a few students to share their definitions with the class and encourage debate, correcting possible misconceptions and reinforcing the correct points.

2. Connection with Practice (3 - 5 minutes):

   • The teacher then asks students to relate the concepts learned to practical everyday situations.
   • For example, he might ask: "How can you apply the concept of electric current in everyday life?"; "What are some examples of direct current and alternating current that you see in your homes?"; "How is electrical resistance used in real-world applications?"
   • The teacher should encourage students to think deeply and provide concrete examples to support their answers.

3. Reflection on Learning (3 - 5 minutes):

   • The teacher asks students to reflect on what they have learned during the lesson.
   • He can ask questions such as: "What was the most important concept learned today?"; "What questions have not yet been answered?"
   • The teacher should encourage students to express their opinions freely and ensure that all questions are answered.

4. Teacher Feedback (1 - 2 minutes):

   • Finally, the teacher provides feedback to the students on their participation and understanding of the lesson.
   • He can praise the students' efforts, acknowledge the interesting ideas that were shared, and offer suggestions for improvement for the next topic.
   • The teacher should encourage students to continue studying the topic at home, reviewing the concepts and solving additional problems.

This Return stage is crucial for consolidating students' learning and for the teacher to assess the effectiveness of their teaching methodology. In addition, it helps to develop students' ability to reflect on what they have learned and to apply the concepts learned in practical situations, which is essential for meaningful learning.

Conclusion (5 - 10 minutes)

1. Summary of Key Concepts (2 - 3 minutes):

   • The teacher should recap the main points covered in the lesson, emphasizing the definition of electric current, the difference between direct current and alternating current, the concept of electrical resistance, and the application of Ohm's law.
   • He can ask students to share the definitions that they remember for each concept, correcting any misunderstandings and reinforcing the correct points.
   • The teacher can then briefly summarize each concept, highlighting its importance and how it applies in the real world.

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

   • The teacher should explain how the lesson connected theory to practice and application.
   • He can mention the everyday examples that were used to illustrate the concepts, such as choosing the wire in an electrical installation and selecting a light bulb for a luminaire.
   • The teacher can also emphasize that the concepts learned in the lesson are the foundation for understanding many other topics in physics and engineering, and that they have practical applications in various areas of life.

3. Extra Materials for Study (1 - 2 minutes):

   • The teacher should suggest additional materials for students who wish to deepen their understanding of the topic.
   • He can recommend reference books, physics websites, educational videos, and circuit simulation apps.
   • The teacher can also suggest additional problems for students to solve at home to practice the concepts learned.

4. Importance of the Topic (1 - 2 minutes):

   • Finally, the teacher should explain the importance of the topic for daily life and for society.
   • He can mention that electricity, which is made possible by electric current, is essential for the functioning of almost everything in our modern lives, from the electronic devices that we use to the transportation and communication systems that depend on it.
   • The teacher can also discuss how understanding electric current and electrical resistance is crucial for energy efficiency and safety in many practical applications, such as the electrical installation of a home or the operation of an electric car.