-
A copper sphere of diameter 18 cm is drawn into a wire of diameter 4 mm. The length of the wire, in metre, is :
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- 2.43
- 243
- 2430
- 24.3
- 2.43
Correct Option: B
| Volume of sphere = | πr³ | |
| 3 |
| = | π × 9 × 9 × 9 | |
| 3 |
= 972π cubic.cm.
If the length of wire be h cm., then
π × (0.2)² × h = 972π
| ⇒ h = | = 24300 cm. | |
| 0.2 × 0.2 |
or 243 metres
