A circuit consists of a 4 Ω resistor, a 6 Ω resistor and a small lamp connected in series with an ideal cell. The lamp is marked 3 V, 0.30 A.
(i) Determine the resistance of the lamp from its marked rating 3 V, 0.30 A.
(ii) Calculate the emf required from the cell so that the lamp receives its rated voltage when connected in series with 4 Ω and 6 Ω resistors.
(iii) The 4 Ω resistor is removed while the cell emf remains the same. Calculate the new current through the lamp and state, with reason, whether the lamp becomes brighter, dimmer or fails to glow.