Four cells each of e.m.f. and internal resistance ohm are connected in series. The combination is connected in series to an ammeter of negligible resistance, a ohm resistor and an unknown resistor . The current in the circuit is . Draw a labelled circuit diagram for the above arrangement and calculate:
(i) The total resistance of the circuit.
(ii) The total e.m.f.
(iii) The value of
(iv) The potential difference across