YOUR POTENTIAL
IS
HIGH!
14. What is Voltage?
Your Potential is High!
Student Instruction Sheet
Challenge
Establish the difference between series and parallel in a circuit. Then,
investigate the relationship between voltage and the number of light bulbs that
are placed in a series circuit or a parallel circuit.
Equipment and Materials
• Computer w/ USB port
• Alligator Clip Leads
• PASPORT USB interface
• Battery Holder (D-Size)
• PASPORT Voltage/Current Sensor
• (2) D Cell Battery
• DataStudio software
• Student Instruction Sheet
• Student Response Sheet
• (3) Lightbulbs and Sockets
Safety Precautions
Remember, follow the directions for using the equipment.
Background
Light bulbs in a series circuit are connected in end-to-end.
If light bulbs are connected in series to a voltage source,
what happens to the brightness of the individual bulbs as
more and more bulbs are added to the “chain”? What will
happen to the voltage across each individual bulb as more
and more bulbs are added to the circuit? If one bulb in a
series circuit is removed, what happens to the rest of the
bulbs?
PS-2810
Student Instruction Sheet 341
14. What is Voltage?
YOUR POTENTIAL
IS
HIGH!
Light bulbs in a parallel circuit are connected side-byside. If light bulbs are connected in parallel to a voltage
source, what happens to the brightness of the individual
bulbs as more and more bulbs are added? What will
happen to the voltage across each individual bulb as more
and more bulbs are added to the circuit? If one bulb in a
parallel circuit is removed, what happens to the rest of the bulbs?
Predict
Before beginning the eLab, complete the prediction portion of the
Student Response Sheet.
Explore
Computer Setup
1. Plug the PASPORT USB interface
into the computer’s USB port.
2. Plug the Voltage/Current
Sensor into the USB
interface. This will
automatically launch the
PASPortal window.
3. Choose the appropriate
DataStudio configuration file
entitled
14 What is Voltage CF.ds
Note: Configuration
files automatically
launch the appropriate
display(s), sampling
rate(s), etc.
342
Student Instruction Sheet PS-2810
YOUR POTENTIAL
IS
HIGH!
14. What is Voltage?
The Voltage/Current Sensor is a
multi-sensor. Since it measures
two distinctly different
quantities, you may find it
challenging to use the sensor
properly. Use the information at
right to guide you in the use of
the Voltage/Current Sensor.
The voltage portion of
the sensor measures
voltage across a part
of a circuit in volts.
The current portion
of the sensor
measures current
through the circuit
in amps.
to the USB link
Record Data
Record Data Part 1: Light Bulbs in Series
1. Set up the equipment as shown in Figure 1.
Start with one light bulb.
2. In DataStudio on the Experiment menu, click
Monitor Data. (You can continue monitoring
data for the rest of the experiment.) Measure
the voltage across the batteries and across
the light bulb. Record the values in Data Table
Part 1A on the Student Response Sheet.
Figure 1
3. Place another light bulb in series with the first.
See Figure 2.
4. Measure the voltage across each light bulb and
both bulbs. Record the values in Data Table Part 1B
on the Student Response Sheet.
Figure 2
5. Place another light bulb in series with the other
two light bulbs. See Figure 3.
6. Measure the voltage across each light bulb and all
the bulbs. Record the values in Data Table Part 1C
on the Student Response Sheet.
Figure 3
7. Remove the light bulb from the middle socket.
What happened? Answer the question on the Student Response Sheet.
8. Replace the light bulb once you have answered the question.
PS-2810
Student Instruction Sheet 343
14. What is Voltage?
YOUR POTENTIAL
IS
Record Data Part 2: Light Bulbs in Parallel
1. Set up the equipment as shown in Figure 4. Start with
one light bulb.
2. Measure the voltage across the batteries and light
bulb. Record the values in Data Table Part 2A on
Student Response Sheet.
Figure 4
(Note: The sensor should still be monitoring the
voltage.)
3. Place another light bulb in parallel with the first. See
Figure 5.
4. Measure the voltage across each light bulb and both
bulbs. Record the values in Data Table Part 2B on the
Student Response Sheet.
Figure 5
5. Place another light bulb parallel with the other
two light bulbs. See Figure 6.
6. Measure the voltage across each light bulb and
all the bulbs. Record the values in Data Table
Part 2C on the Student Response Sheet. Click
the Stop (
Figure 6
) button to end data
monitoring.
Remove the light bulb from the middle socket. What happened? Answer the
question on the Student Response Sheet.
Replace the light bulb once you have answered the question.
Analyze
1. Answer the questions and define the vocabulary words on the Student
Response Sheet.
2. Follow your teacher’s instructions regarding cleaning up your work space.
344
Student Instruction Sheet PS-2810
HIGH!
YOUR POTENTIAL IS HIGH!
14. What is Voltage?
Student Response Sheet
Name:__________________________________
Date:_______________________________
Your Potential Is High!
Vocabulary
Use available resources to find the definitions of the following terms:
parallel circuit: ________________________________________________
___________________________________________________________
series circuit: _________________________________________________
___________________________________________________________
voltage: ______________________________________________________
___________________________________________________________
PS-2810
St udent Response Sheet 351
14. What is Voltage?
YOUR POTENTIAL IS HIGH!
Predict
1. Do you think the voltage in a series circuit will change as more light bulbs are
added to the circuit?
____________________________________________________________
____________________________________________________________
____________________________________________________________
2. How do you think the voltage across the voltage source compares to the
voltage across the light bulbs in a series circuit?
____________________________________________________________
____________________________________________________________
____________________________________________________________
3. Do you think the voltage in a parallel circuit changes as more light bulbs are
added to the circuit?
____________________________________________________________
____________________________________________________________
____________________________________________________________
4. How do you think the voltage across the voltage source compares to the
voltage across the light bulbs in a parallel circuit?
____________________________________________________________
____________________________________________________________
____________________________________________________________
5. Which will burn brighter: 3 light bulbs wired in series or 3 light bulbs wired in
parallel (the amount of voltage supplied being the same in each case)?
____________________________________________________________
____________________________________________________________
____________________________________________________________
352
Student Response Sheet PS-2810
YOUR POTENTIAL IS HIGH!
14. What is Voltage?
Data
Data Table Part 1A (Series, one bulb)
Voltage Across Batteries:
Voltage Across Light Bulb:
Data Table Part 1B (Series, two bulbs)
Voltage Across Light Bulb 1:
Voltage Across Light Bulb 2:
Voltage Across Both Bulbs:
Data Table Part 1C (Series, three bulbs)
Voltage Across Light Bulb 1:
Voltage Across Light Bulb 2:
Voltage Across Light Bulb 3:
Voltage Across All Bulbs:
What happened to the light bulbs when you removed the middle bulb from the
socket? Why?
___________________________________________________________
___________________________________________________________
___________________________________________________________
PS-2810
St udent Response Sheet 353
14. What is Voltage?
YOUR POTENTIAL IS HIGH!
Data Table Part 2A (Parallel, one bulb)
Voltage Across Batteries:
Voltage Across Light Bulb:
Data Table Part 2B (Parallel, two bulbs)
Voltage Across Light Bulb 1:
Voltage Across Light Bulb 2:
Voltage Across Both Bulbs:
Data Table Part 2C (Parallel, three bulbs)
Voltage Across Light Bulb 1:
Voltage Across Light Bulb 2:
Voltage Across Light Bulb 3:
Voltage Across All Bulbs:
What happened to the light bulbs when you removed the middle bulb from the
socket? Why?
___________________________________________________________
___________________________________________________________
___________________________________________________________
Analyze
Use your data to answer the questions.
1. How did the voltage across the batteries compare to the voltage across the
light bulb for Data Table Part1A?
___________________________________________________________
___________________________________________________________
___________________________________________________________
354
Student Response Sheet PS-2810
YOUR POTENTIAL IS HIGH!
14. What is Voltage?
2. Compare the voltage across each light bulb to the voltage of both light bulbs in
Data Table Part 1B.
___________________________________________________________
___________________________________________________________
___________________________________________________________
3. What did you notice about the voltage across each light bulb and the total
voltage across all three light bulbs in Data Table Part 1C?
___________________________________________________________
___________________________________________________________
___________________________________________________________
4. What can you say about the voltage in a series circuit?
___________________________________________________________
___________________________________________________________
___________________________________________________________
5. How did the voltage across the batteries compare to the voltage across the
light bulb for Data Table Part 2A?
___________________________________________________________
___________________________________________________________
___________________________________________________________
6. Compare the voltage across each light bulb to the voltage of both light bulbs in
Data Table Part 2B.
___________________________________________________________
___________________________________________________________
___________________________________________________________
PS-2810
St udent Response Sheet 355
14. What is Voltage?
YOUR POTENTIAL IS HIGH!
7. What did you notice about the voltage across each light bulb and the total
voltage across all three light bulbs in Data Table Part 2C?
___________________________________________________________
___________________________________________________________
___________________________________________________________
8. What can you say about the voltage in a parallel circuit?
___________________________________________________________
___________________________________________________________
___________________________________________________________
Synthesize
1. What can you conclude about the voltage in a series and parallel circuit?
___________________________________________________________
___________________________________________________________
___________________________________________________________
2. How does the magnitude of voltage across a light bulb relate to the brightness
of the bulb?
___________________________________________________________
___________________________________________________________
___________________________________________________________
3. Do your results support your predictions?
___________________________________________________________
___________________________________________________________
___________________________________________________________
356
Student Response Sheet PS-2810