_{Since potential can have any value you want depending on the choice of the reference level of zero potential, how does a voltmeter know what to read when you connect it between two points?}

The potential difference (which is the same as voltage) is equal to the amount of current multiplied by the resistance. A potential difference of one Volt is equal to one Joule of energy being used by one Coulomb of charge when it flows between two points in a circuit.

Solution:

As we know the voltmeter is measuring the relative (due to the reference) potential difference between the two points charges- The voltmeter takes a point as a reference and considers it as zero potentiaL So, it can measure the potential difference betWeen the reference and the selected point charge. Also, the voltameter does the same step as a second point

So, the potential difference between the tWO point charges is measuring-

As We know the voltmeter is measuring the relative (due to the reference) potential difference between the two points charges. The voltmeter takes a point as a reference and considers it as zero potential- 50, it can measure the potential difference betWeen the reference and the selected point charge. Also, the voltameter does the same step as a second point

So, the potential difference between the two-point charges is measuring-