Download Phet circuit lab

Series and Parallel Circuits Basics
Name:_____________________________________________
Period: ______
Directions:
1. Log on to your computer
2. Go to the following website:
http://phet.colorado.edu/index.php
3. Click the button that says “Play with sims…”
4. Click on the application that says Circuit Construction Kit (DC only). It should be the first box.
5. Click “Run now.”
You now have the raw material to create a circuit. Take a moment to look over the site and find all the
different materials. To build a circuit you will need several wires, a light bulb, a voltage source, a voltmeter,
and a non – contact ammeter. Play with it to see how to grab and manipulate these tools. Shorten wires by
clicking and dragging on the yellow circles on the end.
Note: Careful with light bulbs – you must see dots flowing through the filament of the light bulb or you have
not connected them correctly, there is not enough voltage in circuit (batteries) or you have too much
resistance for the voltage you have selected. You can right click to disconnect a wire (split junction) or right
click to remove a component. Play around before beginning to minimize frustration.
Click the reset button.
A. Series Circuits
Build a simple series circuit that consists of 6 pieces of wire, 1 light bulb, and 1 battery (voltage source).
Recall the battery supplies the “push” of electrons. In order to complete the circuit, the red circles at the end
of each must overlap. Please note that the light bulb also has TWO circles. Your circuit is complete and
working when the light comes (blue dots flow through filament and not just the base of the light bulb).
1.
Draw a picture of your circuit on your own sheet of paper and label it SERIES circuit. Use the
correct symbols for a circuit. Refer to your circuit reference sheet for correct symbols if needed.
2. Under your circuit write: The moving dots represent ______________.
Use the tools at the side of the margin to get a voltmeter and a Non-contact ammeter. You must select the
check box for it to appear on your screen. Put the voltmeter near the battery and place the red tab (probe)
at one end of the battery and the black probe at the other.
3.
What is the voltage? __________V. (Record this voltage on your own circuit diagram – see
example done in class.)
4.
Place the red and black probes on either end of a wire. What is the reading include units?
____________.(Record this voltage on your own circuit diagram.)
5.
Place the red and black probes of the voltmeter on either end of the light bulb. What is the reading
- include units? ____________
6.
In order for the voltmeter to read the voltage or potential difference –
Where do you have to have the voltmeter positioned? _____________________________
Why do you think this is so? _____________________
Place the ammeter crosshairs over the moving blue dots.
7. What does the ammeter measure? ___________
8. What is the reading? _______
9. What does this tell us about the circuit?
Use the left button to play with the resistance and voltage of the battery. Make observations on how
this changes the readings on the voltmeter and ammeter. Create a table in the space below and record your
observations. Be sure to record the changes you made and then the effects.
10. Click the advanced tab and alter the resistivity of the wire. Record your observations.
11. What is the resistivity measuring?
Raise your hand and let Ms. Curtis or Mr. Dehart check off your working series circuit.
Click the reset button to begin working on a parallel circuit.
Draw a line on your paper to create a new section and answer questions for parallel circuits.
B. Parallel Circuits
Parallel circuits provide more than one path for electrons to move.
1.
On your own paper sketch a parallel circuit that includes 10 wires, 2 light bulbs and 1 voltage
source. Use your circuit symbols.
2.
Create the circuit you drew with the Phet simulator tool. The blue dots will be moving and both
lights will be on once the circuit is complete. Raise your hand to have your circuit verified. If the
teacher is working with another student – ask a partnering group to verify your circuit – if you are still
unsure – wait until the teacher has confirmed your circuit before moving on to the measurements.
3.
Use the voltmeter and non-contact ammeter to measure electron flow and push. Include units.
Voltage:_______
Ammeter:______
4.
How does this compare with your observations in the series circuit? Is this surprising? WHY or
WHY NOT?
Alter resistance and voltage and create a data table and record your observations below.
Now right click on one of the wires connected to a light bulb. Remove the wire and record your
observations.
5.
Does this affect the voltage, amperes, or visually change the appearance of the light bulb?
Replace the wire. Now remove one of the wires touching the voltage source. What happened?
6.
What is the difference between removing the first wire and the second? Why is this significant?
Comparisons:
Create a second series circuit and record your observations about the two once they are side by
side.
7. Be sure to include how the current, voltage, and electron flow behave in each type of circuit.
Circuit Challenge:
Individually or teams of 2 students.
If you submit an answer that fails, you are out of the running for the extra credit. Your score depends on the highest
level you complete. You only need the circuit to perform the task of last level; previous circuits can be dismantled.
For bonus points to be achieved – you must draw each circuit with the correct symbols and construct the working
circuit.
Levels:
1) Make a light bulb light brightly using 4 batteries.
2) Add an on/off switch.
3) Make 3 light bulbs light brightly with all 3 with the same brightness (same current, measures
the same number of amps).
4) Have a switch that turns on/off 2 of the 3.
5) Have a switch that turns on/off all 3 lights.
6) Make a circuit with one main on/off switch that will turn on/off 3 bulbs, each with a different
brightness.
Use the non-contact Ammeter to check for different currents.
7) Change the circuit so 1 switch will turn on/off all the lights
and a second switch will change the lights
from all being the same brightness
to all being different brightnesses.