exam question about voltmeters and their loading effect on a circuit

Discussion in 'Homework Help' started by bart3b, Jun 12, 2009.

  1. bart3b

    Thread Starter New Member

    Jun 12, 2009
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    I'm half way through dc circuits class and have come to a roadblock, the subject deals with voltmeters and their loading effect.
    The question is: A 15V battery connected in series with a 1kohm resistor is tested with a 20000 ohms per volt voltmeter at the 20V range. What does the circuit measure?
    I'm looking for the formula or combination of formulas needed to solve this. If you can help, thanks.
     
  2. Audioguru

    New Member

    Dec 20, 2007
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    Hint: What is the voltmeter measuring?
     
  3. beenthere

    Retired Moderator

    Apr 20, 2004
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    What is the input resistance of the meter on that scale?
     
  4. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    20000 ohms per volt sensitivity is a 50 uA meter.
     
    Last edited: Jun 12, 2009
  5. bart3b

    Thread Starter New Member

    Jun 12, 2009
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    Meter is measuring voltage in circuit, input R in meter is 400k ohms
     
  6. beenthere

    Retired Moderator

    Apr 20, 2004
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    So far, so good. What do you know about resistors in parallel?
     
  7. bart3b

    Thread Starter New Member

    Jun 12, 2009
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    Voltage is equal across all components. Total current equals the sum of individual branch currents. Total R equals total voltage divided by total current and total resistance is always less than individual branch resistors.
     
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