Problem 3.179

Fig. 3.43 illustrates a potentiometric circuit by means of which we can vary a voltage $V$ applied to a certain device possessing a resistance $R .$ The potentiometer has a length $l$ and a resistance $R_{0},$ and voltage $V_{0}$ is applied to its terminals. Find the voltage $V$ fed to the device as a function of distance $x$ . Analyse separately the case $R \gg R_{0}$ .

\begin{aligned} &\text { 3.179. } V=V_{0} R x /\left[R l+R_{0}(l-x) x / l\right] ; \quad \text { for } \quad R \gg R_{0} \quad V \approx\\ &\approx V_{0} x / l \end{aligned}

Electric Current