Download Series and Parallel Circuits Computer Lab

Name:___________________________
The Basics of Series and Parallel Circuits
Directions:
1. Go to the PhET website: http://phet.colorado.edu/index.php
2. Find “Circuit Construction Kit (DC only)”.
3. 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. When done, click the reset button.
I. Series Circuits
A. Build a simple series circuit that consists of 6 pieces of wire, 1 light bulb, and 1 battery
(voltage source). 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 on and the blue dots begin moving.
B. Draw a picture of your circuit here.
C. What do you think that the moving blue dots represent?
D. Use the tools at the side to get a voltmeter and a non-contact ammeter. Put the voltmeter
near the battery and place the red tab at one end and the black at the other.
What is the voltage? __________
E. Place the non-contact ammeter crosshairs over the moving blue dots.
What is the current? __________
F. Right click on the battery to change the voltage. What happens to the readings on the
voltmeter and ammeter when you triple the voltage of the battery? What happens to
brightness of the light bulb?
Let Mr. Pennington check your work. When he has given the okay, click the reset button.
II. Parallel Circuits
A. Parallel circuits provide more than one path for electrons to move. Sketch a parallel circuit
that includes 10 wires, 2 light bulbs and 1 voltage source. The blue dots will be moving and
both lights will be on once the circuit is complete.
Let Mr. Pennington check your parallel circuit.
B. Use the voltmeter to probe your circuit.
1. What is the voltage across the battery? _______________
2. What is the voltage across the 1st light bulb? _______________
3. What is the voltage across the 2nd light bulb? _______________
C. Use the non-contact ammeter to probe your circuit.
1. What is the current coming out of the battery? _______________
2. What is the current passing through the 1st light bulb? _______________
3. What is the current passing through the 2nd light bulb? _______________
D. Disconnect one wire to the 1st light bulb by right clicking on the connection and clicking on
“Split Junction”.
1. What is the current now coming out of the battery? _______________
2. What is the current passing through the 1st light bulb? _______________
3. What is the current passing through the 2nd light bulb? _______________
4. Has the brightness of the 2nd bulb changed? ______________ Why or why not?