Nonideal voltmeters

  1. Here is the question, for reference:

    I have two equations but am having trouble solving them for V, clearly by eliminating I

    E-(I*r)-(I*R_V)=0
    V_ab=E-(I*R)

    Any help would be appreciated, thanks.
     
  2. jcsd
  3. Nevermind, I got it, but the next problem is giving me a bit of trouble:

    If E = 7.5 volts and r = .45 ohms, find the minimum value of the voltmeter resistance R_V for which the voltmeter reading is within 1.0% of the emf of the battery.

    I am given the following equation to work with:

    E(1-(r/(r+R_V))
     
  4. Nevermind, got that too. Disregard this thread, heh.
     
Know someone interested in this topic? Share a link to this question via email, Google+, Twitter, or Facebook