A 12V battery has an internal resistance of 1Ω. Three identical bulbs, each of resistance 6Ω, are to be operated from this battery.
(i) Draw labelled circuit diagrams for the two separate arrangements: (a) bulbs connected in series, (b) bulbs connected in parallel.
(ii) For each arrangement, calculate the total resistance of the external circuit and the net resistance seen by the battery (include internal resistance).
(iii) Determine the current supplied by the battery and the total power dissipated in the bulbs for each arrangement.
(iv) Which arrangement will make the bulbs glow brighter? Briefly justify your answer, commenting on the role of the battery’s internal resistance.