Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Using a voltmeter

  1. Oct 25, 2008 #1
    1. The problem statement, all variables and given/known data

    A circuit consists of a series combination of 6.00 -kOhm and 4.50 kOhm resistors connected across a 50.0-V battery having negligible internal resistance. You want to measure the true potential difference (that is, the potential difference without the meter present) across the 4.50 -kOhm resistor using a voltmeter having an internal resistance of 10.0 kOhm.

    What potential difference does the voltmeter measure across the 4.50 -kOhm resistor?
    2. Relevant equations

    3. The attempt at a solution
    I tried doing (50*10000)/V - 10,000 = 4500 and solving for V but I got 35.5 and this isn't the right answer. There are no formulas in my book for calculations with voltmeters I got this formula online so I'm not even sure if it is correct can anyone help me out?
  2. jcsd
  3. Oct 25, 2008 #2


    User Avatar
    Homework Helper

    Hi physstudent1,

    Treat the voltmeter as just a resistor being hooked in parallel to the 4.5 kOhm resistor. In this new circuit, what is the potential difference across the 4.5 kOhm resistor?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook