CAPE Physics Unit 2 · 2017 · Paper 1 · Question Q5

Item 5 refers to the following circuit diagram which compares an unknown resistance, X, with known resistances, P, Q and R. [Circuit diagram of a Wheatstone bridge with resistors X, R, P, Q and a galvanometer] If the resistances X, P, Q and R are such that no current flows through the galvanometer, the bridge is said to be balanced. Which of the following relationships BEST represents the ratio \frac{X}{R}?

1. (A)\frac{1}{PQ}
2. (B)PQ
3. (C)\frac{P}{Q}
4. (D)\frac{Q}{P}

This question uses a figure or table from the paper — you'll see it when you practise.