Brief Description:

Students will learn how a circuit works by acting as various components of a circuit.

Grades: 4, 5, 6, 7, 8

Time: 20-30 Minutes

Keywords: circuit, electricity, resistors, current, switches, battery, electrons, charge, introduction to electricity

Lesson Objectives

• Students will begin to understand how electrons flow.
• Students will be able to recognize the function of different components in a circuit.
• Students will practice teamwork by working as a class to create the demonstration.

Materials

• Plastic balls (half labeled with a positive sign and the rest labeled with a negative sign)
• Two buckets: one will act as the proton side of the battery, and the other will act as the negative side of the battery.

• Note: If If you do not have plastic balls to use for this activity, the students themselves can serve as electrons. They will walk in a circle (representing the wire), slow when they come across a resistor, and stop when the switch is open.

Signs that students can wear– resistor, switch, light bulb, battery or motor. (Students linking hands will serve as the wire.)

Procedure

1. Gather students in a circle and tell the students that they are going to act out a circuit. Assign one student to be the battery and explain that the role of a battery is to be the energy source for a circuit. Give him/her the paper sign and put the buckets of balls on either side of him/her. Explain that balls with plus signs are protons, balls with negative signs are electrons, one bucket represents the positive terminal of the battery, another bucket represents the negative terminal of the battery. Explain that the bucket with the protons will not be touched since the electrons will be the ones that move (electron flow).
2. The first student will grab a ball from the electron bucket and pass it on.  Have the students continue passing as long as all students follow the rule that you can only pass the electron if the next student doesn’t already have one.
3. Each electron continues around the circle until the last student drops it into the proton bucket. Explain that all electrons move (current formed) due to attraction to protons, and that is why all the electrons end up in the proton bucket at the end.
4. Once all electrons are used, explain that each student in this circuit acted as wire (a wire is a path for electrons to move through).  Explain that a circuit with only a battery and wire is a short circuit.
5. Explain why short circuits are dangerous, and therefore circuits need resistors. Explain that resistors reduce current flow (like a pinched garden hose) and assign 1-3 students the role of a resistor. The resistor must count 3-5 seconds when the electron reaches them before passing it on to the next student.
6. Do the demonstration again, this time including the resistor(s) in the circuit.
7. In the next iteration, add the switch.
8. Start off with the open switch. Ask the students if the electrons will keep moving or not.  Discuss why. Students who were resistors should keep practicing the role of a resistor.  Once the electron reaches the student acting as the open switch, the flow of electrons should stop. Restart the circuit again this time with a closed switch.  Ask why switches might be used in a circuit.
9. Introduce the last component: the lamp.  When the electrons reach the student acting as a lamp let them recreate what would happen (jump up to show brightness or hold the electron above their head for a moment).
10. Change the circuit around however you like! Give students the opportunity to be different components. Ask the students to make predictions.

Extensions or Modifications:

• Bring in signs of different parts: diodes, fans, etc.
• Transition to using real parts. Allow the kids to freely explore with squishy circuits, snap circuits, etc.

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