Learning cycle: Explanation

Brief overview: This lesson allows the student to learn about series and parallel circuit by working in small groups. The students first predict what the differences are between the two circuits by answering questions and looking at drawings of each circuit. Then they will make a model of the two circuits. They then make predictions about each circuit. After testing their predictions, they compare their results with other groups.

Goals:  The student will develop an understanding of series and parallel circuits by predicting what the differences between the circuits and constructing a model of each circuit. 

Formative Assessment: 

Lesson Organization

Opening: 10 minutes:  The teacher will explain to the students that they will be learning about series and parallel circuits. The teacher will show the students what materials they will be using and how to do the activity.

 

Development: 20 minutes: The students will predict what series and parallel circuits are by looking at a handout with drawings of each circuit (See attached). The students will answer questions to help with their predictions. The students will then make a model of a parallel circuit and a series circuit using the materials provided for them. With guidance and supervision, the teacher will allow the students to figure the circuits out on their own.

 Ending: 20 minutes: The students will answer questions about the models they make (See attached). They will then compare what they found out with other groups.

Instructional Strategies:  Discussion

Teacher Resources:

Enrichment:

Summative assessment:

Activity:  Your activity toay has 3 separate parts. Here is a description of the connection of the circuit for each of the 3.

W h a t i s a S i m p l e C i r c u i t ?

A simple circuit consists of three elements: a source of electricity (battery), a path or conductor on which electricity flows (wire) and an electrical resistor (lamp) which is any device that requires electricity to operate. The illustration below shows a simple circuit containing a battery, two wires, and a low voltage light bulb. The flow of electricity is from the high potential (+) terminal of the battery through the bulb (lighting it up), and back to the negative (-) terminal, in a continual flow.

Schematic Diagram of a Simple Circuit: The following is a schematic diagram of the simple circuit showing the electronic symbols for the battery, switch, and bulb.

What are Series and P a r a l l e l C i r c u i t s ?

Series Circuits: In a series circuit, electricity has only one path on which to travel. In the example to the right, two bulbs are powered by a battery in a series circuit design. Electricity flows from the battery to each bulb, one at a time, in the order they are wired to the circuit. In this case, because the electricity can only flow in one path, if one of the bulbs blew out, the other bulb would not be able to light up because the flow of electric current would have been interrupted. In the same way, if one bulb was unscrewed, the current flow to both bulbs would be interrupted.

Parallel Circuits: In a parallel circuit, electricity has more than one path on which to travel. In the example to the right, two bulbs are powered by a battery in a parallel circuit design. In this case, because the electricity can flow in more than one path, if one of the bulbs blew out, the other bulb would still be able to light up because the flow of electricity to the broken bulb would not stop the flow of electricity to the good bulb. In the same way, if one bulb were unscrewed, it would not prevent the other bulb from lighting up.

What About Resistance: The flow of electricity depends on how much resistance is in the circuit. In our examples, the bulbs provide resistance. In a series circuit, the resistance in the circuit equals the total resistance of all the bulbs. The more bulbs in the circuit, the dimmer they will light. In a parallel circuit, there are multiple paths through which current can flow, so the resistance of the overall circuit is lower than it would be if only one path was available. The lower resistance means that the current will be higher and the bulbs will burn brighter compared to the same number of bulbs arranged in a series circuit.

Safety concerns:

Materials:

Construct both a series circuit and a parallel circuit using the batteries, wires, and bulbs provided to you. Your series circuit will look something like the drawing below:

Draw your own diagram below that illustrates how your Parallel Circuit will look:

Series and Parallel Circuits

Group Predictions

After you have constructed both a series and parallel bulb circuit, make some predictions on the following as a group:

1. Do you think the bulbs in the parallel circuit or the series circuit will burn brighter?
   Explain why:
2. If you remove a bulb in your parallel circuit, with the other bulb(s) still light?
   Explain why:
3. If you remove a bulb in your series circuit, with the other bulb(s) still light?
   Explain why:
4.  

- Laura Wilson