Phy 2 Lab 6

Experiment 06 Guide The Oscilloscope

Adjustments for In-Person Students

Due to the shortened periods due to the pandemic, students can omit procedure 3 of Part 2 and all of Part 3. Students performing the experiment in the laboratory perform all other parts of the procedure.

In-person students should watch the video available on Canvas at Pages > View All Pages. Be aware that GSAs will minimize their introductory instruction time so students have more minutes to complete the procedure without rushing.

Instructions for At-A-Distance Students

All video clips have been saved in one (very large) MP4 video. It is found in Canvas > Pages > View All Pages. Note that some procedures in the manual refer to a square but a sine wave was used when the videos were recorded.

There is not much data to take in this experiment. You can record some observations from scenes in the video. The main tasks, after watching the video is to complete the following exercise to replace portions of the procedure. Be sure to answer questions posed in Part 1 and the first two procedures of Part 2 in the lab manual.

Part 5 - Replaces what remote students cannot perform in Parts 1 and 2

Since several procedures have been eliminated, include this new part in your Data Analysis. Run the following simulations. Include one screen capture for each simulation in your report.

1) This first simulator allows shows how different waves sound and appear when the alternating voltage creating the sound appears on an oscilloscope-like screen.

http://www.physics-chemistry-interactive-flash-animation.com/ electricity_electromagnetism_interactive/ oscilloscope_description_tutorial_sounds_frequency.htm

2) This next simulator is a somewhat true to real life.

http://eleceng.dit.ie/dsp/elab/

3) Here is one that is actually an Excel spreadsheet.

http://www.engineers-excel.com/Apps/Oscilloscope/Description.htm

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Part 6 - Replaces Part 4 for Remote Students

1) Create an Excel spreadsheet that demonstrates sine-wave superposition. In other words, plot two sine functions with two different frequencies on the same y-axis with angle (in radians) on the x-axis. Add a third graph that is the sum of first two functions. Make a screen capture for your report and include the cells containing the equations. Display the equations used (see procedure 4b below).

2) Duplicate the previous spreadsheet but only plot the sum of the two sine functions. Adjust the frequencies to produce beats. Make make screen captures of two trials and paste them into the Data section your report.

3) There are plenty of YouTube videos of Lissajous figures. Watch these two videos.

https://www.youtube.com/watch?v=yfxbY0C1tXw

https://www.youtube.com/watch?v=uPbzhxYTioM

4) Create an Excel spreadsheet where you plot two different sine (or cosine) functions, one on the x-axis and one on the y-axis. Generate your own Lissajous figure. Remember that Excel expects angles to be in radians inside of its trigonometric functions.

a. Be sure to copy the equations you use into a cell just below the column heading but above the values to show the reader the equation.

b. Use the ‘trick’ of copying the cell’s equation and before pasting it, insert a blank space in the cell to prevent Excel from recognizing what you are going to paste as an equation. Then create a screen capture of your Lissajous Figure simulator (including the equations) and paste it into your report.

5) Lissajous figures that use triangle and square waves are very cool. Here is a link for the Excel formula necessary to produce a triangle wave. Despite what is written in the link, this formula does not use VBA, which is a Microsoft Add-on called Virtual Basic for Applications. Create an Excel spreadsheet that creates a Lissajous figure of two different triangle waves. Again, include a screen capture in your report.

https://www.quora.com/What-is-the-code-to-create-a-triangle-waveform-in-Excel-using- VBA-coding-given-the-frequency-of-10kHz-and-amplitude-of-+-1

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