Measuring Voltage Divider Output with Real Voltmeters

AI Thread Summary
To measure the output of a voltage divider using real voltmeters, one must account for the effective resistance of the voltmeter, which affects the voltage reading. Unlike an ideal voltmeter, which is treated as having infinite resistance, a real voltmeter has a finite resistance that alters the voltage divider's output. The voltage measured can be calculated by modeling the voltmeter as a resistance in parallel with R2. This adjustment leads to a new voltage divider equation that incorporates the voltmeter's resistance. Understanding this concept is crucial for accurate voltage measurements in practical applications.
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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!
 
Physics news on Phys.org
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.
 

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