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The diameter of a copper sphere is 1 8 cm. The sphere is melted and is drawn into a long wire of uniform circular cross-section. If the length of the wire is 108 m, the diameter of the wire is
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- 1 cm
- 0.9cm
- 0.3 cm
- 0.6 cm
- 1 cm
Correct Option: D
| Volume of sphere = | πr³ | |
| 3 |
| = | × π × 9 × 9 × 9 | |
| 3 |
= 972π cu. cm
Let the radius of wire be R cm, then
πR² × 10800 = 972π
| ⇒ R² = | = 0.09 | |
| 10800 |
⇒ R = √0.09
= 0.3 cm
∴ Diameter = 2 × 0.3 = 0.6 cm
