1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Voltmeter reading problem

  1. Feb 9, 2015 #1
    1. The problem statement, all variables and given/known data
    The voltmeter in the figure below reads 6.2 V. If the vs = 12 V and R1 = 560 Ω, R2 = 470 Ω,
    R3 = 680 Ω, and R4 = 4.7 kΩ, is the voltmeter reading correct?
    2. Relevant equations
    V*Rx/(Ry+Rx)

    3. The attempt at a solution
    So I thought the voltage in the voltmeter would equal the voltage across the 4.7kohm resistor

    So 12V*4700/(4700+560+470+680)= 8.798 V
    So my answer would be no.

    Is this correct or am I doing it wrong?
     

    Attached Files:

    • 1f1.png
      1f1.png
      File size:
      42.2 KB
      Views:
      65
  2. jcsd
  3. Feb 9, 2015 #2

    phinds

    User Avatar
    Gold Member
    2016 Award

    HUH ???

    Do you understand how to reduce series and parallel resistors?
     
    Last edited by a moderator: Feb 9, 2015
  4. Feb 9, 2015 #3
    Opps, should it look more like this?

    R1+R2=1030 ohms
    R3||R4=594 ohms

    12 V * 594/(1030+594)= 4.389 V

    Which is exactly half of my old answer for some reason.
     
  5. Feb 9, 2015 #4

    phinds

    User Avatar
    Gold Member
    2016 Award

    Now it looks right
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Voltmeter reading problem
  1. Voltmeter Problem (Replies: 4)

  2. Loading voltmeter (Replies: 5)

Loading...