Physics (AS & A Level) · Oct / Nov 2017 · Paper 13 · Question 34

A simple circuit comprises a source of electromotive force (e.m.f.) connected to a load. How does the output power P of the source depend on the internal resistance r of the source and the resistance R of the load?

1. A$P$ is independent of both $r$ and $R$.
2. B$P$ depends on $r$ but not on $R$.
3. C$P$ depends on $R$ but not on $r$.
4. D$P$ depends on both $r$ and $R$.

As printed in the paper