ENGR 43
Lab Activity
Student Guide
LAB 9 – RC and L/R Circuits - Phasors
Student Name: ___________________________________________________
Overview
Getting Started
In this lab activity, you will simulate series
and parallel RL and RC circuits in Multisim,
and then verify the simulation by manually
analyzing the circuits using impedance
formulas. You will then construct the
circuits and compare your data with the
simulations. Finally you will present your
results in table and graph form in Excel.
Lab Activity and Deliverables:
It should take students approximately 2
hours to complete the lab activity, and 1
hour of homework time to complete the lab
report.
Before Starting This Activity
The student should be able to:
 Perform basic word processing and
spreadsheet editing
 Perform basic MultiSim circuit
simulation and editing
 Operate the NI-ELVIS hardware and
VIs.
 Calculate XL and XC
Equipment & Supplies
Item
NI-ELVIS trainer
1 mH inductor
0.01 µF capacitor
1k Ω resistor
Quantity
1
1
1
1
Special Safety Requirements
None
Lab Preparation
Learning Outcomes For Activity
Install the standard trainer board on the
ELVIS platform, if not already installed.
Relevant knowledge (K), skill (S), or
attitude (A) student learning outcomes
K1. Calculate impedance, voltage, and
current in series and parallel RL and
RC circuits
S1. Produce an AC analysis data series in
Multisim and export to Excel
S2. Compile data into a test report.
S3. Present data in table and chart form
S4. Measure and characterize RL and RC
circuits
A1. Recognize the circuit interactions
between frequency and reactive
components.
LAB 9 – RC and L/R Circuits - Phasors 1
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© 2012
ENGR 43
Lab Activity
Student Guide
Task #1 – Series RL Circuit
1. Download the lab worksheet
E60lab2.xlsx and the four MultiSim
files, E60Lab2-(RL1, RL2, RC1,
RC2).ms10, from the GoogleDocs site.
Open the worksheet in Excel and open
the E60Lab2-RL1 file in MultiSim.
V(rms): 1.00 V
I(rms): 1.00 mA
Freq.: 1.00 kHz
R1
Probe3,Probe1
1kΩ
U1
V1
1.414 Vpk
1kHz
0°
+
1.000
V
Probe4,Probe2
V(rms): 6.28 mV
I(rms): 1.00 mA
Freq.: 1.00 kHz
L1
1mH
AC 10MOhm
XSC1
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Figure 1
2. Note that this simulation uses the
Measurement Probe tool to display
multiple circuit measurements at the
points labeled Probe 1 and Probe 2. The
voltage displayed is relative to the circuit
ground, and the current is flowing
through the wire at that point. To display
the voltage across R1 we use the virtual
meter because neither terminal of R1
connects to ground.
3. Use the AC analysis tool to measure the
following, from 100 Hz to 1Mhz. Use 5
steps per decade.
4. Series current, I(probe 1)
5. Source voltage, V(probe 1)
6. Voltage across L1, V(probe2)
7. Export the data to Excel. Copy and paste
the data into the appropriate cells of the
table in Part 1 of the worksheet (on the
Series RL tab).
8. If necessary, open the Grapher window
(from the VIEW menu in MultiSim).
Note the small red arrow next to the
Magnitude display on the left side of the
window. Click on the Phase graph and
note that the red arrow points to the
LAB 9 – RC and L/R Circuits - Phasors 2
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phase graph. Repeat the data export to
Excel, only this time the phase data will
be exported. Copy and paste the data
into the appropriate cells of the table in
Part 1 of the worksheet.
9. For the 10 kHz, 158 kHz, and 1 MHz
frequencies, calculate XL and Z for the
circuit, converting the rectangular
notation to polar form. Calculate the
current flow by dividing the impedance
into the source voltage and express the
result in polar form. Enter your results in
Table 2.
10. Build the circuit on the ELVIS
protoboard and measure the source and
inductor voltages and phase shift at the
same frequencies in step 6 with the
oscilloscope virtual instrument. Can you
accurately collect all the data? Can you
see the same phase relationship as you
saw in the simulation? Explain why or
why not in the Summary Sheet. Enter
your results in Table 2.
Task #2 – Parallel RL Circuit
V(rms): 1.00 V
I(rms): 1.00 mA
Freq.: 1.00 kHz
Probe3,Probe1
V1
1.414 Vpk
1kHz
0°
R1
1kΩ
L1
1mH
XSC1
Probe4,Probe2
V(rms): 0 V
I(rms): 1.00 mA
Freq.: 1.00 kHz
Probe1,Probe3
V(rms): 0 V
I(rms): 62.8 uA
Freq.: 1.00 kHz
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Figure 2
1. Open the E60Lab2-RL2 file in
MultiSim. Note that Probe 1 shows the
voltage across all components and the
total current, and Probe 2 and Probe 3
show the branch currents through the
resistor and inductor.
© 2012
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ENGR 43
Lab Activity
Student Guide
2. Click on the Parallel RL tab on the Excel
workbook. Repeat the simulation and
calculations in steps 2 through 6 of the
previous section for the three currents,
XL and Z. Enter your data in tables 3 and
4. You do not need to build the circuit
and take measurements.
Task #3 – Series RC Circuit
1. Download Open the E60Lab2-RC1 file
in MultiSim.
V(rms): 1.00 V
I(rms): 1.00 mA
Freq.: 1.00 kHz
R1
Probe3,Probe1
1kΩ
V1
1.414 Vpk
1kHz
0°
U1
+
1.000
V
AC 10MOhm
V(rms): 6.28 mV
Probe4,Probe2
I(rms): 1.00 mA
Freq.: 1.00 kHz
C1
0.01µF
10%
XSC1
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be exported. Copy and paste the data
into the appropriate cells of the table in
Part 5 of the worksheet.
5. For the 1 kHz, 15.8 kHz, and 100 kHz
frequencies, calculate XC and Z for the
circuit, converting the rectangular
notation to polar form. Calculate the
current flow by dividing the impedance
into the source voltage and express the
result in polar form. Enter your results in
Table 6.
6. Build the circuit on the ELVIS
protoboard and measure the source and
capacitor voltages and phase shift at the
same frequencies in step 5 with the
oscilloscope virtual instrument. Can you
accurately collect all the data? Can you
see the same phase relationship as you
saw in the simulation? Explain why or
why not in the Summary Sheet. Enter
your results in Table 6.
Figure 3
Task #4 – Parallel RC Circuit
2. Use the AC analysis tool to measure the
following, from 100 Hz to 1Mhz. Use 5
steps per decade.
a. Series current, I(probe 1)
b. Source voltage, V(probe 1)
c. Voltage across C1, V(probe2)
3. Export the data to Excel. Copy and paste
the data into the appropriate cells of the
table in Part 1 of the worksheet (on the
Series RC tab).
4. If necessary, open the Grapher window
(from the VIEW menu in MultiSim).
Note the small red arrow next to the
Magnitude display on the left side of the
window. Click on the Phase graph and
note that the red arrow points to the
phase graph. Repeat the data export to
Excel, only this time the phase data will
LAB 9 – RC and L/R Circuits - Phasors 3
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V(rms): 1.00 V
I(rms): 1.00 mA
Freq.: 1.00 kHz
Probe3,Probe1
C1
V1
1.414 Vpk
1kHz
0°
R1
1kΩ
.01µF
10%
XSC1
Probe4,Probe2
V(rms): 0 V
I(rms): 1.00 mA
Freq.: 1.00 kHz
Probe1,Probe3
V(rms): 0 V
I(rms): 62.8 uA
Freq.: 1.00 kHz
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Figure 4
1. Open the E60Lab2-RC2 file in
MultiSim. Note that Probe 1 shows the
voltage across all components and the
total current, and Probe 2 and Probe 3
show the branch currents through the
resistor and capacitor.
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ENGR 43
Lab Activity
Student Guide
2. Click on the Parallel RC tab on the Excel
workbook. Repeat the simulation and
calculations in steps 2 through 5 of the
previous section for the three currents,
XC and Z. Enter your data in tables 7 and
8. You do not need to build the circuit
and take measurements.
Deliverable(s)
Print your completed Lab Excel Worksheet
and save it with this activity guide in your
Lab Activity Binder.
Lab 2 Summary Questions
Series RL Circuit
What effect does frequency have on an RL series circuit? What impact does this have on
collecting the data in a real circuit?
Examine your data from this activity. How would increasing the resistance affect the circuit?
How would increasing the inductance affect the circuit?
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© 2012
ENGR 43
Lab Activity
Student Guide
Parallel RL Circuit
What effect does frequency have on an RL parallel circuit? What impact does this have on
collecting the data in a real circuit?
Examine your data from this activity. How would increasing the resistance affect the circuit?
How would increasing the inductance affect the circuit?
Series RC Circuit
What effect does frequency have on an RC series circuit? What impact does this have on
collecting the data in a real circuit?
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© 2012
ENGR 43
Lab Activity
Student Guide
Examine your data from this activity. How would increasing the resistance affect the circuit?
How would increasing the capacitance affect the circuit?
Parallel RC Circuit
What effect does frequency have on an RC parallel circuit? What impact does this have on
collecting the data in a real circuit?
Examine your data from this activity. How would increasing the resistance affect the circuit?
How would increasing the capacitance affect the circuit?
Lab 9
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© 2012