In the circuit of a small heater, a resistor R1=5Ω is connected in series with a parallel network consisting of a 10Ω resistor (R2) and an unknown resistor Rx. The circuit is powered by a 24V DC supply. When the heater is switched on, the current through R1 is measured to be 2.0A. Assume all resistances remain constant during operation.
(i) Calculate the total resistance of the circuit.
(ii) Determine the equivalent resistance of the parallel branch.
(iii) Using your answer from part (ii), compute the value of the unknown resistor Rx.