Two capacitors P and Q, each of capacitance C, are connected in series with a battery of e.m.f. 9.0 V, as shown in Fig. 6.1. [Figure 6.1] A switch S is used to connect either a third capacitor T, also of capacitance C, or a resistor R, in parallel with capacitor P.

1. (a)(i)Switch S is in position X. Calculate the combined capacitance, in terms of C, of the three capacitors,[2]
2. (a)(ii)the potential difference across capacitor Q. Explain your working.[2]
3. (b)Switch S is now moved to position Y. State what happens to the potential difference across capacitor P and across capacitor Q.[4]

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