Three incandescent bulbs of 100 W each are connected in series in an electric circuit. In another circuit another set of three bulbs of the same wattage are connected in parallel to the same source.

(a) Will the bulb in the two circuits glow with the same brightness? Justify your answer.

(b) Now let one bulb in both the circuits get fused. Will the rest of the bulbs continue to glow in each circuit? Give reason.

(a) The bulbs which are in parallel connection will glow with more brightness than with series connection bulbs because in parallel connection, bulbs are connected with the same source. So, power in each bulb will be:

P = V² /2R whereas in series Power through each bulb will be P= V² /9R Therefore, bulbs in parallel connection will glow more.

(b) If one bulb in series circuit is fused then all the bulbs in the series circuit will get fused but in cause of parallel circuit, if one bulb fused the other two fused will continue to glow because in case of series circuit, same amount of current is distributed whereas in case of parallel circuit, the current is divided among electrical gadgets and is therefore, each bulb has different value of resistance and requires different current to operate.