Optimizing Voltmeter Accuracy: High or Low External Resistance?

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The accuracy of a voltmeter is influenced by its internal resistance and the external resistance it measures. A lower external resistance may minimize the impact of the voltmeter's internal resistance, but measuring low values can introduce challenges. To determine optimal external resistance, one should consult voltmeter specifications, noting accuracy ratings across different resistance ranges. Additionally, understanding how voltmeters measure voltage—through current or voltage sampling—can clarify the relationship between internal and external resistances. Ultimately, the most accurate measurement occurs when the external resistance is appropriately matched to the voltmeter's specifications.
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Homework Statement



For what external resistance is the voltmeter most accurate (a high resistance or a low resistance)? (given that the voltmeter is not ideal and does have an internal resistance not equal to infinity)

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The Attempt at a Solution



On first thought i said that it would be when the external resistance is smallest seeing as the effect of the internal resistance should be smallest. But then again accuratelly measuring smaller values is supposed to be difficult...
 
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I won't give a direct answer...

Take two approaches -
1 - look at websites for voltmeters and review spec sheets - what do you consider low vs high reistance - ranges vary by orders of magnitude. There will be an accuracy spec for each range, from this what do you conclude?

2 - How does a voltmeter measure resistance? by sampling current or voltage? draw a circuit diagram of the voltmeter with the test load - be sure to include the the internal resistance of the voltmeter - if the voltmeters components are 1% accurate components, how much does the measurement change?
 
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