Big Idea Electricity and magnetism are related effects that have many useful applications such as conversion to heat, motion, and sound. Guiding Questions • 1. How can two light bulbs glow equally bright with one battery? • 2. How does electricity flow through a parallel circuit? • 3. How is a parallel circuit different from a series circuit?
Yesterday we found out that two light bulbs connected with one D-cell in the simple series circuit did not produce enough light for the group to move around the cave. We then noticed that by adding another D cell (battery) to the circuit made the bulbs glow equally bright. But the group is now concerned that if two D cells (batteries) are used, the energy supply available at the moment could finish before finding a way out of the cave (battery). We have to save energy by finding a way to make the two light bulbs produce an equally bright light but using only one D cell battery.
Think and talk about… • What does the group in the cave want to do to the circuit? • Why is it important for the group to conserve energy? • What is the goal of the group?
Focus Question • Write a question in your notebook that is related to the scenario and can be investigated. • Your question should be correctly written; capital letter and ending punctuation. • Your question should not be able to be answered with a yes or no. • You do not need to have the same question as your group.
Class Focus Question How can we make two light bulbs glow equally bright with only one D cell battery?
Think about it… How many paths does electricity have on a series circuit to flow through? What can you do to allow the energy to flow equally to both bulbs from one D-cell? Besides using just one battery and two light bulbs, what component can the group change in the series circuit to save energy?
Prediction I think if we connect the ______________________________________________ then _____________________________________________ because _________ _____________________________________________. Plan Make drawing of how you think you can connect the battery, 2 light bulbs and wires to create light that scores 3 – brighter than the control circuit.
Data collection Group A Group B Each light bulb is brighter than the control circuit Each light bulb is not as bright as the control circuit or has no light Use this symbol on circuits you tried that did not give a bright light.
Meaning Making Conference • What do the Group A drawings tell us about how energy flows? • What claim can we make about the flow of energy in diagram A if we remove one of the light bulbs? • What do the Group B drawings tell us about how energy flows? • What claim can we make about the flow of energy in diagram B if we remove one of the light bulbs? Introduce parallel circuits Circuits that have multiple pathways for the current to flow are called parallel circuits. Remember, circuits that have only one pathway are called series circuits.
Claims and Evidence I claim that… I know that…. I claim this because… I know this because….
Conclusion My thinking has changed since I made my original prediction. I used to think ________________________________________________________, but now I know _______________________________________________________ ____________________________________________________________________. Today I learned__________________________________________ Reflection I wonder if it’s possible to… OR I wonder how…