Fundamental Properties of AC Circuits & Lab – Week 1 Lab

Alternating Voltage and Current

1. Watch Week 1 Video Lectures: Introduction to Virtual Instruments from the weekly content and the Introduction to Virtual Breadboarding in MultiSIM.

a. Please note that the virtual breadboard circuitry in the "Week 1 Video Lecture 2 - Introduction to Virtual Breadboarding in MultiSIM" is incorrect and should be modified. Check this document to correct the circuitry in the video to run the DCR and Connectivity check: Modified Circuit Design

2. For problem 1 in the Week 1 Assignment, fill in the Calculated column using 3 Vrms at 60 Hz as your source. All calculations and measurements should be done for RMS only. Make sure that you show your work as required. Now construct the circuit. Use the Agilent function generator for the source.

3. Using the Agilent multimeter, measure the voltages across the source and each resistor and fill out the chart below. Do not forget to put units on the chart. Be sure to provide a screenshot showing the measurement of VR1 with the connections to the Agilent function generator and Agilent multimeter clearly visible. INCLUDE THE TIME STAMP SHOWN IN MULTISIM IN ALL SCREENSHOTS FOR THIS COURSE. (Not including the time stamp can result in a grade of 1.)  Also, use the multimeter to measure IT and RT (hint: remove the voltage source to measure RT). Provide a screenshot of each of these measurements.

	Calculated	Agilent Multimeter	Tektronix Oscilloscope
VT =
VR1 =
VR2 =
VR3 =
IT =			N/A
RT =			N/A

4. Now repeat the measurements using the Tektronix oscilloscope and fill out the chart above (IT and RT are not required). An oscilloscope is designed primarily for voltage, frequency, and period measurements.  Current can be measured with a special probe called a current probe (which can be found in Multisim).  Resistance cannot be measured with an oscilloscope.   (For the Tektronix Oscope, look for Cyc RMS).  Provide a screenshot of at least one voltage measurement using the scope. Note what is required in order to duplicate the Agilent multimeter measurement.

5. Show the calculated and measured period of the signal from the Tektronics Oscilloscope.  (Don't forget to click through the menu button on the scope.)  Provide a screenshot of the measurement.

Calculated period: (source frequency 60 Hz)

Measured period:

6. Now change the values of R1 given below in the table and use Tektronix oscilloscope to record the RMS Voltage measurement across each resistor. Do not forget to add units in the chart. Take screenshots to show your work for the period measurement as well for at least one case of R1. The screenshots should show the settings of the Agilent signal generator and o-scope along with the waveforms.

7. Complete the following chart:

Source frequency 60Hz	Tektronix Oscope Measurement
R1 = 5 kohms	VR1 =
	VR2 =
	VR3 =
R1 = 10 kohms	VR1 =
	VR2 =
	VR3 =
R1 = 15 kohms	VR1 =
	VR2 =
	VR3 =
R1 = 25 kohms	VR1 =
	VR2 =
	VR3 =
Source frequency 100Hz	Tektronix Oscope Measurement
R1 = 25 kohms	VR1 =
Source frequency 200Hz	Tektronix Oscope Measurement
R1 = 25 kohms	VR1 =

8. Based on your measurements, answer the following questions:

a. Did your calculated and measured values match? If not, why?

b. Does the multimeter give you the peak, peak-to-peak, or rms measurement?

c. How did you obtain the same measurement on the Tektronix oscilloscope that you obtained using the Agilent multimeter?

d. What is the industry practice to report AC measurements? Peak value or RMS value?

e. Describe the effect of increasing R1 on the total resistance of the circuit.

f. Describe and explain the effect of RT on the value of IT for a given value of VT.

g. Does resistance depend on frequency? For a purely resistive circuit, does the voltage or current change as the frequency changes?

Lab Template - This lab template should be used in reporting your lab reports in all of your labs.

Create your lab report and submit as ET115W1LabYourGID.docx, or an equivalent word processing file extension.

Rules for lab submissions:

1. The lab document must be a Word document.  PDF files are NOT accepted.

2. All screenshots must be included.

3. All Multisim screenshots must include the date/time stamp. See TOOLS AND TEMPLATES for the procedure to display the date and time.

4. Any and all Multisim files must be submitted. 

5. Any equations used must be typed in Word.  Copy and paste of equations from outside sources is prohibited.

6. No graphics are allowed in the Word document other than screenshots of circuits from Multisim and hardware if applicable, with the date/time stamp.

7. The lab template should be used.  Specifically, it is brought to your attention that a summary MUST be provided explaining the results of the labs, the relationship of the results to expected results, and any challenges encountered.

8. Hardware portion of labs should include screenshots of the assembled circuit with your name and student GID number written on paper next to the circuit. There should be screenshots of the instrument readings with the date and time stamp on lower right corner clearly shown. See example below.

Any violation of the submission rules above will result in a grade of 1.