Problem: 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.

FREE Expert Solution

1)

Kirchhoff's loop rule:

$\boxed{\mathbf{\Sigma }\mathbf{V}\mathbf{=}\mathbf{0}}$

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

i = V_meter/R_v