Electricity UnitCircuit Breakers

Teacher of the Lesson: Kelly Pelak
Grade Level: 5
Estimated Time: 40-45 minutes

OBJECTIVES:

MATERIALS:

Each group will need:

PROCEDURES:

Introduction

  1. Before the lesson begins, gather the materials at the back table. Place each group's materials in a zip-lock bag and set out additional materials in case the students should need them. Gather the students at their desks and begin a discussion about the types of things that may interrupt a circuit. Explain that switches are one example of a device that can interrupt a circuit. Other devices, such as circuit breakers and fuses, do the same thing. Circuit breakers work as a weak link in a circuit and are designed to stop the flow of electricity if the circuit begins to get too hot.
  2. Briefly discuss the importance of these safety devices with the students. What would happen if electrical circuits were not equipped with fuses or circuit breakers?
  3. Explain that the students will be exploring the role of a circuit breaker in an electrical circuit by creating their own model of a circuit breaker. While this model may not work EXACTLY like normal circuit breakers, students will have an opportunity to see how a circuit breaker will stop the flow of electricity when the circuit becomes too hot.

Sequence of Instruction

  1. Draw a diagram on the board of the circuit that they will be constructing. Briefly discuss the students' predictions and ask them to hypothesize about the most significant factors in their circuits. What do you think will happen if we add batteries to the circuit? What if we decrease the number of wool strands? How might these factors affect the outcome of the experiment?
  2. Discuss the directions on the instruction sheet . Make sure that the children understand that the balloons may pop, and that they should keep their eyes away from the balloon when the circuit is completed. Also, remind students that each group gets only 2 balloons. If they pop both of them right away-- that is it! Remind students to carefully follow the directions on the instruction sheet. The first balloon is a test, the second involves a challenge. The students may find it necessary to modify the instructions a little bit. Rather than using only aluminum foil, students may choose to use a combination of foil and wire.
  3. Review expectations for group work. Provide an alternative assignment for students who choose to goof around. Inform students of who they will be working with. Release students and allow them to get started.
  4. Walk around the room and monitor what the groups are doing. Make sure that students can explain why the balloon either popped or didn't pop.

Closure

  1. Discuss the results of their experiments and have each group reflect and answer questions about their work. Why does the balloon pop? How could you change your circuit breaker so that the balloon would not pop until three batteries were added to the circuit? How could you modify the circuit breaker so that the balloon would pop with only one battery?

EVIDENCE OF STUDENTS ACHIEVING OBJECTIVES:

  1. Were students able to demonstrate a clear understanding of the function of circuit breakers in their written or verbal responses? Were the students able to set up a working circuit? Was it apparent that the students knew why the balloon popped in some circumstances and not others?
  2. Were students able to follow directions and work harmoniously in their groups? Did the students respect others in their groups? Did the groups work effectively as a team?

ADAPTATIONS:

REFLECTION:

  1. How did I do?
  2. Were the students engaged in the activity?
  3. Did the students understand the importance of circuit breakers?
  4. Did the students respect one another during group work?

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