Physics (AS & A Level) · May / June 2017 · Paper 13 · Question 36

A potential divider circuit consists of a cell of negligible internal resistance in series with two variable resistors of resistances R1 and R2. The potential difference (p.d.) across the cell is V0. The p.d. at the output is V. [circuit diagram] Which statement is correct?

1. AWhen R1 increases, it takes a greater proportion of V0, so V decreases.
2. BWhen R1 increases, the current through R1 and R2 decreases, so V increases.
3. CWhen R2 decreases, it takes a smaller proportion of V0, so V increases.
4. DWhen R2 increases, the current through R1 and R2 decreases, so V decreases.

As printed in the paper