Calculating a voltmeter reading
List out what you know from the problem

E = 9 V

R1 = R2 = R = 1 kΩ

Rv = 10 kΩ


It can help to redraw the circuit to make how you're thinking about it clearer.


Apply the handy two parallel resister formula 

     Rv x R2   10 x 1   10
Rp = ------- = ------ = -- kΩ
     Rv + R2   10 + 1   11


The simplified circuit is now two resisters in series. 







simulate this circuit &ndash; Schematic created using CircuitLab

Apply the voltage division rule

         Rp            10 / 11          10 / 11       10     30
Ep = E ------- = 9 --------------- = 9 --------- = 9 ---- = ---- ~ 4.3 V
       R1 + Rp      1 + (10 / 11)       21 / 11       21      7


Ep will be what the voltmeter (V) will read. This is within 95% of what theory predicts an idealized voltmeter (∞Ω) would have measured (4.5v). Which is not bad considering the voltmeter only has 10 times the resistance of the resisters.

You can check these results in the sites handy Circuit Lab:








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