Multiple choice

The radius of a sphere 9 cm. it is melted and cast into wire of radius 0.3 cm. Find the length of wire एक गोले की त्रिज्या 9 सेमी. है। उसे पिघलाकर एक तार बनाया जाता है, जिसकी त्रिज्या 0ण्3 सेमी. है तो तार की लम्बाई ज्ञात कीजिए।

  1. 0.8 metre/मीटर

  2. 324 metre/मीटर

  3. 810 metre/मीटर

  4. 108 metre/मीटर
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D Correct answer
Explanation

Volume of sphere = (4/3)π(9)^3 = 972π cm³. Volume of cylinder (wire) = π(0.3)²h. Equating volumes: π(0.09)h = 972π, so h = 972/0.09 = 10,800 cm = 108 m. The wire radius 0.3 cm must be used correctly in the calculation.

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