There are four potential divider circuits, and each one is formed from a battery with electromotive force (e.m.f.) $9\,\text{V}$ and negligible internal resistance, linked to a set of resistors. In every circuit, the resistors have resistance values of $X$ or $2X$. Which circuit gives the greatest output voltage $V$?
Physics 9702 · AS & A Level · Potential dividers