### Big Idea - Lewiston Independent School District #1

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
Class Focus Question
How can we make two light bulbs glow equally
bright with only one D cell battery?
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
Each light bulb is brighter
than the control circuit
Group B
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…