Open office or excel formatting

Discussion in 'Homework Help' started by TBayBoy, Sep 21, 2011.

  1. TBayBoy

    Thread Starter Member

    May 25, 2011
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    I'm working on a lab on parallel resonant RLC circuit and am trying to format my table so it is both human readable and computes the correct values from the measured voltage at Rs1 (990 ohms)

    any advice would help as I'm drawing a blank on this.
     
  2. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    1,164
    Tbay,

    Can you provide the lab instructions?
     
  3. TBayBoy

    Thread Starter Member

    May 25, 2011
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    Essentially the lab was to construct a series, and then parallel RLC circuit, calculate a resonant frequency, and then using a signal generator push a 1 Vp-p sinusoidal wave through, and make measurements with the oscope.

    In this section I was to use the oscope to put the tank circuit in phase between source and output, then reduce the frequency from the resonance taking measurements at the sense resistor. repeat increasing the frequency.

    From these measurements calculate current and impedance. I feel good about the numbers, calculated but I want to use a spreadsheet to put into the report, and create a current vs impedance graphs from.

    to do this everything in the sheet is in scientific notation, so I want to format it in a more human readable form.
     
  4. SgtWookie

    Expert

    Jul 17, 2007
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    Wait a minute... your VRS1 column you have labeled as mV. The first number is 1.5E-1, which is, of course, 0.15 - but you're calculating it as voltage rather than mV when you divided it by 990 Ohms to get your current.

    Or, are you talking fractions of uA's now?

    Is that first number supposed to be 150mV, or 0.15 Volts?

    Then next column you have labeled I uA. Are those really microamperes, or supposed to be mA's?

    Because 0.15v or 150mV / 990 Ohms is 152uA or 0.152mA or 1.52E-4 Amperes, not 1.52E-4 uA.

    [eta]
    Anyway, I put your stuff in a spreadsheet, then I used the =celladdress function to copy everything to another area of the spreadsheet, then used "Format Cells" and "Number", and selected either 1 or 2 decimal places.

    I also multiplied the numbers up by 1e3 for the mA and 1e6 for the uA.
     
    Last edited: Sep 21, 2011
  5. TBayBoy

    Thread Starter Member

    May 25, 2011
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    This is essentially the problem, to do the calculations in spreadsheet I needed it to be done in Amps but I need to display on the sheet in mA so I can graph it in mA.
     
  6. SgtWookie

    Expert

    Jul 17, 2007
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    As long as you have labels as to what the scale of the variables are, I don't see where you will have a problem. Just try to convert them to the most readable format.

    See the attachment I posted in my prior reply.
     
  7. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    Tbay,

    You also thought the spreadsheet, in scientific notation, was calculating things incorrectly.

    if you want to read in amperes, and you wanted to see all the leading zeros, you'd have to format the columns to six places (microamperes) or whatever you wanted.

    When you do the graphs, you can have a different format on the numbers than the spreadsheet, one in scientific notation and the other with leading zeros.

    Other than the two titles, mV and uA, I saw nothing wrong with your original display, except that it would be better if you had consistency in the number of decimal places with your scientific notations and other numbers.
     
  8. Georacer

    Moderator

    Nov 25, 2009
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    I can only talk about excel, which I only use:

    When I want to write very small numbers but want to keep readability, I write the numbers in their submultiples form. When I want to use these numbers in an equation I just add the correct dividend in the expression.

    For example, say if I want the table to present XmV, then I will write my expression as I=X/R*10^(-3)
     
  9. TBayBoy

    Thread Starter Member

    May 25, 2011
    148
    19
    Thanks guys, got it going now :)
     
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