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Two 120 V light bulbs, one 25 W and othe...

Two 120 V light bulbs, one 25 W and other of 100 W were connected in series across a 22 V line. One bulb burnt out instananeously. Which one was burnt and Why ?

Text Solution

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`P=(V^(2))/(R) rArr R=(V^(2))/(P) R alpha (1)/(P)`
P-power, R- resistance
25 W bulb has more resistance . In the series circuit same circuit flows through both the bulbs. The 25 W bulb develops more heat `(H=I^(2)Rt)` and hence burns out almost instantaneously.
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