(a)[2]
State the meaning of the potential difference across a resistor.
(b(i))[2]
Calculate the current in the 40 Ω resistor.
(b(ii))[2]
Calculate the electromotive force (e.m.f.) of the battery.
(c)[2]
State and explain which of the three voltmeters (0-2 V, 0-20 V and 0-200 V) is best for measuring this p.d.
(d(i))[2]
Calculate the power $P$ produced in the 10 Ω resistor.
(d(ii))[1]
Suggest why a resistor with a power rating of $\frac{1}{2}P$ is not suitable for the circuit in Fig. 10.1.
(e)[4]
Fill in the table in Fig. 10.3 to show the effect of connecting resistor R. For each quantity, state whether it increases, decreases or stays unchanged and briefly explain why any change happens. No calculations are needed.