# Problem: Unlike the idealized voltmeter, a real voltmeter has a resistance that is not infinitely large.(a) 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.(b) 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.

###### FREE Expert Solution
84% (273 ratings)
###### FREE Expert Solution

1)

Kirchhoff's loop rule:

$\overline{){\mathbf{\Sigma }}{\mathbf{V}}{\mathbf{=}}{\mathbf{0}}}$

$\begin{array}{rcl}\mathbf{\epsilon }\mathbf{-}\mathbf{ir}\mathbf{-}{\mathbf{iR}}_{\mathbf{v}}& \mathbf{=}& \mathbf{0}\end{array}$

i = Vmeter/Rv

84% (273 ratings) ###### Problem Details

Unlike the idealized voltmeter, a real voltmeter has a resistance that is not infinitely large.
(a) 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.
(b) 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.