Measuring Voltage Divider Output with Real Voltmeters

[dancergirlie]

Homework Statement

How do you measure the output of a voltage divider with real voltmeters that have effective resistances

Homework Equations

The Attempt at a Solution

I know that for an ideal voltmeter (one with infinite resistance), the voltage divider is R2/(R1+R2), but I don't know what to do when the voltmeters have effective resistances. Any help would be great!

 

[Quiablo]

Instead of considering the voltmeter as an effective "open circuit" at the point of measurement, which is equivalent to an infinite parallel resistance, substitute it for (i.e. model it as) a finite resistance, say Rv.