# Problem: A heart pacemaker fires exactly 69 times a minute, each time a 29.0 nF capacitor is charged (by a battery in series with a resistor) to 0.732 of its full voltage. What is the value of the resistance?

###### FREE Expert Solution

In this problem, we will find the value of resistance from the expression of voltage across a charged capacitor, which is expressed as:

$\overline{){\mathbf{V}}{\mathbf{=}}{{\mathbf{V}}}_{{\mathbf{0}}}{\mathbf{\left(}}{\mathbf{1}}{\mathbf{-}}{{\mathbf{e}}}^{\mathbf{-}\frac{\mathbf{t}}{\mathbf{R}\mathbf{C}}}{\mathbf{\right)}}}$

The voltage, V  = 0.732V0

We get time taken by the heart pacemaker to fire once as:

t = 1min/69 = 60s/69 = 0.8696 s

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###### Problem Details

A heart pacemaker fires exactly 69 times a minute, each time a 29.0 nF capacitor is charged (by a battery in series with a resistor) to 0.732 of its full voltage. What is the value of the resistance?