IMPORTANT ANNOUNCEMENTS

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        OSCILLOSCOPE
SPECIAL NOTES:
This lab is spread out over two weeks.
We want you to better understand parametric plots.
This is one of our ways of accomplishing that.

The first week perform parts A and B in the lab manual.

The second week perform part C.
END SPECIAL NOTES
 

MOVIES

Please note: If the movie is too small,
please watch via youtube using the YOUTUBE button on bottom right of each video.
And, some videos have much higher quality. Find the HD version using the gear icon.
WEEK 1:

Oscilloscope, Week 1: Part 1, HP Function Generator 



Oscilloscope, Week 1: Part 2, Oscilloscope Screen 



Oscilloscope, Week 1: Part 3, Oscilloscope Knobs 



Oscilloscope, Week 1: Part 4, Data Taking 



WEEK 2: Lissajou Figures:

Oscilloscope, Week 2: Part 6, Lissajous


Oscilloscope, Week 2: Part 7, Lissajous Excel


Oscilloscope, Week 2: Part 8, Lissajous Mathematica





For our Aviation Students in PHY 1250:





Begin Q&A Forum for "OSCILLOSCOPE"

I am working on the Oscilloscope & Lissajou Figures pre-lab and I am confused on how to read the Lissajou Figures correctly. Can you help?Anonymous
Thu. 05, Sep 2002, 18:06

Dear Student,
Next time PLEASE ask your question FROM the web page that your questions is about (ie. Oscilloscope). You asked this at the Schedule page. Okay, now on to your question. (Visit the Oscilloscope page to see this answer in html...)

The Lissajou ratio is the Vertical axis Frequency to the Horizontal axis Frequency. A ratio of 700 to 300 would be called a 7 to 3 (or 7/3 or 7:3). It would look like it hit the vertical axis boundary 7 times and the horizontal axis boundary 3 times. The vertical boundary (hold on to your hat) is an imaginary horizontal line that is placed at the maximum vertical amplitude. The horizontal boundary is an imaginary vertical line that is placed at the horizontal amplitude extremes. This is tough to say in words. So look at the picture to the right.
Go to the Public Folder (link at top of lab web pages) and find the LabII Templates. Find the Lissajous directory and look at the MSExcel file and Movie.
Douglas
Fri. 06, Sep 2002, 07:11

Douglas,
I'm wondering when you ask for three sig figs. do you want the number out to the thrid decimal place or do you want only three sig figs total? For example, 45,235.06374 would be 45,235.064 or do you want 45,200? Thanks for your help!
Anonymous
Tue. 17, Sep 2002, 15:17
The number 45,235.06374 good to the third decimal place is 45,235.064.
Or in Scientific Notation 4.5235064E4.
The number 45,235.06374 with three significant figures is 4.52E4 or 45,200.
Douglas
Wed. 18, Sep 2002, 09:43

did you get my post lab for the oscilloscope lab? The computer was freaking out, and then when I clicked finish, it said I only got a 33%. Is that really accurate? I know that at least 1/2 of the questions required and essay-type response. shouldn't I at least have the opportunity to get 1/2 credit? =( Thanks!Corrigan, Monica
Tue. 10, Jun 2003, 14:08
mcorriga@gonzaga.edu
You won't know your score until the essays are graded.
Douglas
Tue. 10, Jun 2003, 15:58

Hi Douglas,
I was reading a message within this web page and in the "pre-information" for the Oscilliscope/Lissajou Figures Lab that there is a template regarding information about Lissajou Figures. I looked under the Public Folder and found nothing but information about FTP and no area that mentioned even Lab II Templates. Am I missing where this is located?
Thank You
Anonymous
Tue. 10, Jun 2003, 23:23
S.U.,
Sorry about that. All needed templates and movies are on the CD-Rom for MUSCD Physics Lab 2.
Douglas
Wed. 11, Jun 2003, 05:48

I have tried #9 in the pre-lab twice and have gotten it wrong. If there are four periods, shouldn't the frequency be 0.25, or do you want a whole number so it's just 1.Anonymous
Fri. 05, Sep 2003, 15:47
This is kinda a big point in the lab. If you can't figure it out from the lab manual or spreadsheet template, I know it is fully described in the movies. Sorry to challenge you this way, but this is part of the quiz.Douglas
Fri. 05, Sep 2003, 17:37

Douglas, I am trying to do the pre-lab and the information given in the lab book is very vague. I need to know where I can get better information. Do I have to use the CD-ROM? Anonymous
Sun. 07, Sep 2003, 17:04
Actually, between the manual and the write-up, you should be able to find all your answers; and not in a vague way. The movies make things even more clear.
Douglas
Mon. 08, Sep 2003, 05:21

Where can I find details about systematic and random error?Anonymous
Fri. 20, Feb 2004, 10:51
Your instructor should have covered this in class. I am so sorry if they didn't.
Random error can be seen in the HPDial data table. The data you measured with the slope creates a "scatter" plot. Some of the data is slightly above the best fit line; some is slightly below. Some are 1% below, others are 1.5% below... You can see this in the data table itself. Just scan your eyes down the OScope Freq. column and you will see how sporadic the data appears. When you perform a linear fit on data and R^2 = 1, then the data has no (or very, very little) random error in it.
The HPDial graph has a vertical intercept. This is evidence of a systematic offset of the data. All the data is shifted up or down by the same amount, thus producing a vertical intercept.
Compare/Contrast the HPDial evidence of systematic/random error to the HP Range buttons' graph.
Again, I am so sorry if you your instructor didn't spend time talking about this in class.
Douglas
Fri. 20, Feb 2004, 11:47

Douglas -
I submitted my quiz and it said my score was 3/4 but didn't tell me which question I got wrong as on some of the previous quizzes. Is this because the essays are included in the final score so the grading is not accurate or are there certain questions that it grades and certain ones that you grade? If so how can I find out the question I missed?
craig, crystal
Sun. 05, Feb 2006, 18:14
crystalcraig@hotmail.com
The PostLab will not tell you which ones you missed.
The grade listed is only for those the computer could assess.
The total grade will come a week or so later after the essays are manually graded. At that point, the "Key" is turned on for you to see the quiz, your answers, your points awarded, as well as the correct answers.
I hope this makes sense,
Douglas
Douglas
Mon. 06, Feb 2006, 08:33

I went to do the pre-lab for the second week of the Oscilloscope lab, but it said the time had expired. Is there only one pre and post lab for the two-week lab?
Thanks
Trotter, Jennifer
Wed. 21, Feb 2007, 14:32
jjohn72@hotmail.com
As stated on the schedule page:
"** Two-week labs: There is 1 PreLab before the two weeks.
And there is 1 PostLab after the two weeks."
Douglas
Fri. 23, Feb 2007, 09:35

I am having a probelm understanding question with number 9, I cant find adequate information in the manual/ write up section. Can you explain it?Dwaik, Insherah
Wed. 30, May 2007, 20:59
insherah1437@yahoo.com
Insherah,
Look very carefully at the DataTable. Follow the column titles (which include formulas) and hopefully that will help.
Find the total time for n cycles using the s/div given.
Divide that total time by n to find the period.
Invert the period to find the frequency.
Douglas
Thu. 31, May 2007, 04:56

Whats Up Douglas,
Hope all is well, I just have a question about #4 on the Oscope postlab. How many equations did you want us to list. Did you just want the real vs. hp equation?
Anonymous
Thu. 25, Sep 2008, 23:01
Two equations exist for the dial. The first is HP Dial Range 1000-10,000 Hz. The second is from Lissajou measurments which was HP Dial Range 100-1,000 Hz. Yes, both equation should be of the form:
Real f [Hz] = ______ HP f[Hz] + ______[Hz] for frequency range ...[Hz]
Douglas
Fri. 26, Sep 2008, 09:17

For question number 9 on the pre lab should I take the total number of seconds/total divisions to get total time? And if that is so I get a small frequency which is why Im thinking that it might be wrong.Anonymous
Thu. 11, Feb 2010, 15:18
Total Number of Divisions * (Sec/Div setting) is Total Time.
Total Time divided by Number of Cycles is Period.
Frequency is the Inverse of Period.
John Martinez
Fri. 12, Feb 2010, 12:00

Hi Doug,
On question 7 of the prelab, is period being used synonymously with cycle, or is the question wanting a number that is total time in seconds divided by the number of cycles? I understand that to get total time I need to multiply the number of time divisions by the number of seconds per division, which I see is 5 milliseconds. When I divide that answer by the number of cycles, it says my answer is incorrect. Since I got question 9 right with the inverse of the period I calculated, I'm not sure what is wrong with my answer. Is there a particular number of sig figs I should use to answer the question?
Thanks!
Anonymous
Mon. 19, Sep 2011, 17:56
Period = Time[s] / ((1 Cycle)[Cycles]

Question 7 does not ask for how many seconds (I believe the answer you gave was in seconds.) but for how many periods. If I told you a class period is 2 hours long and that someone had classes from 8am - 2pm, then asked how many classes did they take...
3 class periods.
It was six hours, but 3 periods.
BTW: we could also say there were 3 class cycles (Or, three cycles of classes.)

So, yes, besides units, the number of cycles equals the number of periods.
Douglas
Tue. 20, Sep 2011, 03:18

Hi Doug
I a, ahving trouble with question 2 where it ask how many second is each division if the time sweeps is set to 0.5 ms per division. Would it be 500 sec equal to 0.5 ms?
Thanks!
Anonymous
Wed. 01, Feb 2012, 19:14
The question is asking you to convert from milliseconds to seconds.
It takes 1000 milliseconds to make a second.
Please see Nist for a review of metric prefixes:
https://physics.nist.gov/cuu/Units/prefixes.html

Douglas
Thu. 02, Feb 2012, 04:55

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