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.
Answers
Explanation :-
Q.(a) Will the bulb in the two circuits glow with the same brightness? Justify your answer.
Ans :- Resistance of the bulbs in series will be three times the resistance of single bulb. Hence, the current in the series combination will be one-third compared to current in each bulb in parallel combination. The parallel combination bulbs will glow more brightly.
Q.(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
Ans :- The bulbs in series combination will stop glowing as the circuit is broken and current is zero. However the bulbs in parallel combination shall continue to glow with the same brightness.
Answer:
a)No
b)In first circuit it will not glow.In second circuit it will glow.
Explanation:
a)In the series circuit the Voltage is not constant and each bulbs use ⅓ of the total voltage.So each bulb will glow with ⅓ of the brightness.
In the parallel circuit the Voltage is constant and each bulb will glow with equal brightness
b)In the first circuit the current is constant,so if one bulb fuses the current will stop flowing completely.
In the second circuit the current is not constant so it is distributed by ⅓ in each bulb.So even if one bulb fuses, current will flow through the other 2 bulbs