ENGAGE

What is Happening in a Short Circuit? [5 mins]

Ask students to write any questions they have about what is happening with the string of lights. Have a spot in the room for students to post their questions. You will refer to these questions after the activities to see if the students found out the answers. You might want to ask some students questions like:

• Why do some lights in the series turn off when one of the lights burns out or is taken out? Possible answers: because the lights are part of the same circuit.
• Why are the other lights in the series still on? Possible answers: because they are part of a different circuit
• Have you ever had a situation in your house where there was a short circuit and lights in several rooms of the house went off but in other rooms they stayed on? Why do you think that happened?

If students don’t know the answers, these will be great questions to add to the chart. 

NOTE: Refrain from answering questions at this point in the lesson. Students will figure out the answers as they complete the activities in this lesson.

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INTERACT

Making Different Types of Circuits [30 mins]

Distribute series circuit template, simple circuit template and parallel circuit template

Script: The two different types of circuits we are learning about today are series circuits and parallel circuits. Series and parallel circuits are both simple circuits which means they only have few components that make up the circuit. A series circuit is when there is only one path that the current can flow through and a parallel circuit is when there is more than one path a circuit can take. We will be demonstrating the circuits by creating paper circuits: simple, series and parallel. 

You will be given three different templates that show the types of circuit including a simple circuit which is like the circuit we created in Lesson 2. You will also be given five LEDs, three batteries, scissors, masking tape and conductive tape. 

Make sure they are using the same colored LEDs together. You could split it up so that everyone is working on the simple circuit first, then move on to the series circuit next and end with the parallel circuit. If there is not enough time, you could have them do just the series and parallel circuits.

1. All you need to do is apply the conductive tape on the template on the circuit lines. Remember that conductive means that it allows electricity to flow through so the tape allows electricity to flow through it. At the corners, make sure you use the conductive tape to bend and fold. If you are unable to bend and fold at the corners, make sure the conductive tape overlaps each other and touch the connection points in the corner to make sure they are touching. You can use scissors to cut the tape.
2. The next step is attaching the LED. If you notice, the LED has a long leg and a short leg. The long leg is positive and the short leg is negative. As you see in the diagram, the positive or long leg will be on the right. Mark the longer leg with a marker. Go ahead and fold the legs of the LED at a 90 degree angle so that the longer leg(positive) is on the right and the shorter leg is on the left.
3. Next, use small pieces of the conductive tape to attach the leg to the right side of the conductive tape.
4. Take some conductive tape and roll it into a ball with the adhesive side facing out and stick it inside the batter circle that is gray.
5. Lastly place the coin cell battery on top of the conductive tape ball with the negative side of the battery facing down and the positive side of the battery facing up.
6. Now is the time to test to see if your circuit is working properly. Fold the corner of the conductive tape along the line on the corner so that the conductive tape touches the top of the battery. Once you do that, it should light up the circuit.
7. Now do this for the parallel and series circuit, making sure that you put the conductive tape on the lines and the LED lights where it says to as well as the battery.

Script: Now that you have finished the activity, look at your series and parallel circuit. Do you see how the parallel circuit has more than one way the electricity can flow so if we were to disconnect the flow to one of the LEDs, the other one would still work because there is another way it can flow through. You also see that the series circuit has only one path it can flow through so if we disconnect one LED from the path, the other LED would not light up.

Now that you know about parallel and series circuits, which type of circuit is the christmas light. … If you remember, when we removed one light bulb, the rest stopped working for half of it, which circuit is that like? …. The answer is series circuit because that means there is only one path the electricity can flow through and when one is removed, the other cannot light up. What about the other half of the lights that were lit up even when we removed the light bulb? … That’s right, that would be parallel circuits. What we have here is a mixture of both, where a series circuit one both sides where half of the lights are connected to each other and the other half is connected to each other but both halves are parallel to each other. Which means half of it is still working even if the other half is not working. At your house, what type of circuit do you think your lights are connected to?.... They are made up of parallel circuits because if both lights are on in the kitchen and the bathroom and you turn off the lights in the bathroom, the kitchen lights are still on right?... Unless you turn the kitchen lights off as well, you can turn off one light without making all the lights in your house turn off. This means the light bulbs have more than one path for the current to flow.

*This activity was inspired by and adapted from: https://www.makerspaces.com/simple-series-and-parallel-paper-circuits/