(a(i))[2]
State the name of the component marked X and give its function in this circuit.
(a(ii))[3]
Describe how the circuit in Fig. 10.1 may be used to determine the resistance of the fixed resistor R.
(b(i))[3]
Calculate the current through the heater.
(b(ii))[1]
Suggest a fuse rating to fit into the mains plug for the heater.