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Multimeter problem

  1. Dec 6, 2011 #1
    Hello, i'm trying to learn some electronics by myself but it's quite difficult, now i'm studying the multimeters and a problem says

    What will a 20000Ω/V meter read on its 1 volt scale, when attached to a 1 volt source with an internal resistance of 10k?

    Can you set up this problem for me because I didn't yet understood well the argument. Thank you!
     
  2. jcsd
  3. Dec 6, 2011 #2

    Averagesupernova

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    Analog meters have an ohms per volt spec. This means that if the meter a 20,000 ohms per volt spec and has a 10 volt range that means that the load the probes will put on a circuit while in the 10 volt range would be 200,000 ohms. So do the math figuring a series circuit of 10K ohms with 200K ohms and a 1 volt source.
     
  4. Dec 6, 2011 #3
    It is equivalent to having the voltmeter in series with a resistance R1 of 10k and another R2 of 20k.

    Use V = IR to find V2 which is the reading of the voltmeter.
     
  5. Jan 27, 2012 #4
    But doesn't an high resistance mean a lower sensibility (because it "resist" to more electrons)? Instead why it's the opposite here?
     
  6. Jan 27, 2012 #5

    phinds

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    I don't understand what you just said, but here's the thing: high resistance in a meter means the meter will have less effect on the circuit that it is measuring because it will draw less current out of it. That's a good thing.
     
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