Script: Welcome, everyone! You have been asked by the Ingenia Engineering Association (IEA) to join a team of apprentice engineers.The IEA is organizing a parade called Light Up! where the clothing will be engineered to light up. As apprentice engineers, you will be in charge of designing hats that light up. In order to do that, you will be learning how to turn lights on.
Ask students to brainstorm in their group what materials they think they need to do this.Write out any questions they have about how to turn a light on. Have a place in the room where students can write their questions so you can refer to them later in the lesson and check that they can answer their own question after the activities.
Script: This week, we will be learning all about circuits and how to light things up. Before we start the lesson, I want to know what you think about how light switches work. Turn the light in the room on and off a couple times. Look at the students and ask:
NOTE: Do not provide scientific explanation quite yet. Allow students time to discuss in a small group the answers to these questions. Students should then draw a model that shows how they think the switch is connected to the light and how it works. They should keep these model drawings at hand so they are able to change them as the lesson progresses. They should share their drawings with their team members and discuss their ideas.
Provide each group with a AA battery and ask them to explore the battery. Ask them to write down what they notice on paper. To guide their exploration, ask questions such as:
Hopefully your students will notice that the battery has a negative and a positive side. After students notice this, ask:
Script: Now that we have observed the battery, you will be given aluminum foil, tape and one LED light bulb to design how they can work together to light up the light bulb.
Display for students another battery, a piece of aluminum foil, tape, scissors and one LED light bulb. Let them know that there is a way to turn on the LED light using just these materials!
Ask students to draw a design of how they can use these materials to turn on the LED. After they draw their first design, give them hints asking how the positive and negative side of the battery come into play with their design? You could also talk about an LED having a positive and negative side where the longer leg means positive and the shorter leg means negative side. Then give them time to update their drawing.
After that, you could let them know that the two sides cannot touch. Ultimately, you want the students to end up with the same design as shown in the circuit walkthrough video so that when they implement the design, it is correct. You could end up drawing what the end design should look like on the board and have students compare it to what they have and make the changes.
SAFETY TIP: It is important that they have the design correct because if it isn’t and they for example have the negative side of the aluminum foil touching the positive side, the foil and the battery will get hot which could burn the students.
Script: You will now be able to experiment with the materials and test out the design. Using the materials provided, implement your design to see if it would light up the LED. If your design did not work, think about what you could do differently and test that idea out.
Hand out the materials and have students use the materials that were passed out to them to build and test the design based on their drawings.
After most students have lit up the LED, ask them to look at their design and see how they could edit their design to create a switch that turns the light on and off. Once they have designed it, they can then implement their drawings. Once they have done that, demonstrate so that all students can implement a switch (see instructions in the Answer Key below).
After the demonstration, watch the video that explains how batteries work and then another video on how the electrical circuit works.
Answer Key
Students should connect one of the prongs on the LED to the positive side of the battery with the foil and the other side of the LED to the negative side. If the light doesn’t turn on it is possible that the circuit is incomplete, that the foil is not connecting well to the battery, that they connected the light bulb to only one side of the battery. For a switch, students could cut their foil a point so they can connect it and disconnect it or lift the tape at one of the poles of the battery.
Script: The path we created to make the LED light up is called a circuit. The circuit is made up of electrical current which is made of electrons. The electrons have to travel and they do so in a circuit kind of like running around in a circular race track. It goes from the battery through a conductive material, then onto what we would like to power up in this case the LED and then goes back into the battery. A conductive material is a material that allows electricity to go through. We are going to learn all about conductivity tomorrow.
Now, we are going to watch a short video on how a battery works to see how what we observed about the battery has to do with how it functions.
Watch How do Batteries work? Video (Mocomi.com)
Script: From the video we know that a battery has a positive side and a negative side which is one of the observations we made earlier. Do you remember what the video called the name of the positive side of the battery? …. That’s right, the positive side is called a cathode. What about the negative side? …. The negative side is called an anode. We see that the electrons flow from the negative side of the battery to the positive side of the battery until there are no more electrons left on the negative side and that’s when a battery dies. When working with batteries, it is important to know about voltage and volts. Voltage is the electric force that causes electrons to flow so it’s the push that causes electrons to move in circuit. Volt is the unit of measurement to describe the voltage. It’s kind of like if you wanted to measure water, you would say a cup of water where the cup is a unit of measurement. In the same way, to measure the voltage, you would say volts. In our circuit, if you look at one of the batteries, you will notice that it has 1.5 volts written on it. We used two batteries and placed it on top of each other so that it equaled 3 volts. We needed 3 volts because it takes 3 volts to power the LED. If we were to only use only one battery which is 1.5 volts, it wouldn’t turn on the LED because it wouldn’t have enough power.
Now, we are going to watch another video that talks more about how electrical circuits work.
Watch The Power of Circuit (https://www.youtube.com/@SciShowKids)
Script: In the video, we learned that electricity flows from the power source which is the battery on the path of the circuit which leads to whatever we want to power. In our experiment, we wanted to power the LED. As the electricity went through the LED, the LED lit up and then it left the LED and went back into the battery. This is what we saw in the how to battery work video. As long as there is no space in the circuit, the LED would stay lit. When we added a switch in the experiment, we had to create a break or a space in the circuit. When the switch was on, there was no space in the circuit so the LED stays lit. When we turn the switch off, we open up a space in the circuit. The electricity can’t jump over the space so it can’t reach the LED so it stayed off. To summarize, a circuit is the route or path an electrical current flows in which the path of the circuit has to end where it started with no gaps to make a complete circuit. These electrical current provides energy to power lots of things in our daily lives like microphones and cell phones.
Prompt students to explain how their circuits worked. Encourage them to use the vocabulary they just learned and engage students in a discussion to come up with definitions for the following terms:
Battery: Ask: what was the role of the battery? The battery stores and produces electricity through a chemical reaction. Essentially, it is the power source.
Circuit: Ask: What is the name of the device they built? It is a circuit. A circuit is a path that allows electricity to flow.
Anode: Introduce this term to students by explaining that the positive part of a battery is an example of an anode.
Cathode: Introduce this term to students by explaining that the negative part of a battery is an example of a cathode.
Switch: Allows one to make space in a circuit so we can turn the circuit on and off.
Ask students to go back to their original model of how a light circuit works and revise it to show what they learned in today’s lesson. Prompt students to use some of the vocabulary they learned and add labels to their model.
Battery: power source where the electricity comes from
Circuit: the path that electric current flows
Anode: the positive part of a battery
Cathode: the negative part of a battery
Conductive Material: a materials that allows electricity to flow through
Switch: a space in a circuit that allows a circuit to be turned on and off
Voltage: name of electric force that causes electrons to flow
Volt: units to describe voltage
Script: Now that you understand how you can light things up and how electrical circuits work, we are going to watch two videos that talk about what electrical engineers do.
Show both the following videos to connect the activities to the job of an electrical engineer:
https://www.youtube.com/watch?v=z0lWPIMwYLI (https://engineering.berkeley.edu/) https://www.youtube.com/watch?v=ujrEme2UoLM (www.youtube.com/@TheMEProgram)
After watching both videos, ask students to discuss:
Tell students to think how in a house there are many lights. Give students another LED and ask them if they can change their design in order to light up more than one bulb. They will be involved in a trial and error process. Once they have changed their design to include another LED, have them implement it and test it out. If students have trouble lighting a second LED, ask them:
Ask students to design a flashlight that they can create with materials they find at home. They don’t have to build it but they should create a design on paper describing the materials they would use and how their DIY flashlight would work. If they are able to create a working model, they can!
Consider showing the following video for some inspiration:
