Two identical incandescent lamps are connected to the same d.c. source, first in series and then in parallel.
(i) Describe qualitatively how the brightness of the lamps differs in the two arrangements.
(ii) Explain, without performing detailed numerical calculations, which arrangement draws a larger current from the source.
(iii) Taking the resistance of each lamp as R and the supply voltage as V, show algebraically which arrangement consumes more electrical energy in a given time t.