Download LS-03-circuitactivity-2014-1

NIE 2014
Waterman and Stanley
In “Shine the Lights” Rajee and Jiaming want to link many strings of lights together to speed up testing.
Her father thinks that’s not a good idea. Let’s see if we can figure this out.
Go to PhET simulation https://phet.colorado.edu/en/simulation/circuit-construction-kit-ac
Click the green Run Now! button.
You must have Java enabled in order to run PhET simulations. If you do
not have Java, this will lead you to a download screen for it.
This simulation allows modeling of circuits in either DC or AC mode.
We will use DC mode
Once the simulation opens you will see a workspace, materials and equipment.
You can change the background color by clicking on Options.
To start: Choose “medium” size, and “lifelike” appearance
HINT: It is helpful to start building circuits by using two
segments of wire on each side of the battery. This lets
you add and subtract wires at the various joints AND
helps you keep track of the circuitry more easily than if
only one segment is used on each side. See the figure
below.
 Drag wires to change lengths.
 Right click on junctions to split them and
to open (interrupt) the circuit.
1. Choose one battery. Change its voltage to 20 volts by right clicking on it.
LS-03
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NIE 2014
Waterman and Stanley
2. Create a circuit using the one 20 volt battery, wires and 1 light bulb. When the bulb is lit up, do
the following
a. Use the non-contact ammeter to measure the current at various points in the circuit.
Record your data in the table below.
b. Use the voltmeter by placing the red lead on a wire to the left of the battery and the
black lead or the other side of the battery. What is the voltage? Record your data in the
table.
Number
of bulbs
Simple circuit
3.
Voltage
before
bulbs
Voltage
after
bulbs
Amps
before
bulbs
Amps
after
bulbs
1
Using another wire and bulb, add a second bulb to this circuit to create a series circuit.
a. Predict the effect this second bulb will have on voltage (before the bulbs and between
them.
b. Predict the effect of this second bulb on current:
4.
After the bulbs are lit up measure and record voltage and current as before.
Circuit type
Number
of bulbs
Series
2
Voltage
before
bulbs
Voltage
between
bulbs
Voltage
after
bulbs
Amps
before
bulbs
Amps
between
bulbs
Amps
after
bulbs
5. Do the data support your prediction? Explain
6. Given the information so far, do you think Rajee and Jiaming would be able to explain why
Rajee’s father advised against putting 10 strings of lights together? If so, give an explanation. If
not, suggest some additional factors they could explore.
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