Question

The diagram shows two ways of connecting three lamps P, Q and R to A.C. supply of 220 V.

Name the two arrangements. Which of them would you prefer in a household circuit? Give a reason for your answer.

Answer 1

The arrangement is shown in the figure (i) is a series arrangement. The arrangement in figure (ii) is the parallel arrangement.
We prefer a parallel arrangement. The reasons are:
(i) In series arrangement, if one of the bulbs is fused, the other bulbs also cease to glow. But in a parallel arrangement, if one bulb fuses, the other bulbs continue to glow.
(ii) In the series arrangement, while one bulb glows if the other bulb is switched on, the resistance of the circuit increases, and hence the bulbs glow less bright. But in a parallel arrangement, each bulb glows at the same voltage, therefore the glow of a bulb is unaffected if another bulb is switched on.