Kirchhoff's loop rule:
i = Vmeter/Rv
1) Unlike the idealized voltmeter, a real voltmeter has a resistance that is not infinitely large.
A voltmeter with resistance Rv is connected across the terminals of a battery of emf "EMF" and internal resistance r. Find the potential difference Vmeter measured by the voltmeter.
2) If emf = 7.50 v and r = 0.45 Ω, find the minimum value of the voltmeter resistance Rv for which the voltmeter reading is within 1.0% of the emf of the battery.