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100 points with steps plsTwo electric bulbs rated 200 V, 80 W and 200 V, 40 W respectively are connected in series. If the voltage across the combination is 200 V, the power consumed by the 80 W bulb will be about. (a) 7W (b) 9W (c) 16 W (d) 20 W (e) 5W |
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Answer» 100 W bulbs is smaller than across 60 W bulbGiven:The rating of the first bulb is 200 V−100 WThe rating of the SECOND bulb is 200 V−60 WThe resistance of the first bulb is:R 1 = 100200 2 ⇒400 ΩThe resistance of the second bulb is:R 2 = 60200 2 ⇒ 32000 ΩSince the two bulbs are connected in SERIES,The EQUIVALENT resistance of the circuit is:R eq =400+ 32000 ⇒ 33200 So the current drawn is I= 3200/3200 = 16033 Now, the voltage drop is given as V=IRSo, the voltage will be higher for the higher values of the resistance. So, the bulb of 100 W has less potential as compared to bulb of 60 |
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