The length of a wire (in cm) of 0.1mm radius that can be drawn from melting a solid copper sphere of diameter 6 cm is:
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Correct answer: D
Explanation
The correct answer is option 4 i.e. 360000
6 cm = 60 mm
Volume of the copper sphere = Volume of wire
Volume of sphere = (4/3) × (22/7) × r3
⇒ (4/3) × (22/7) × (30)3
Volume of cylindrical wire = (22/7) × r2 × h
⇒ (22/7) × (0.1)2 × h
So, (4/3) × (22/7) × (0.3)3 = (22/7) × (0.1)2 × h
⇒ (4/3) × (27000) = (1/1000) × h
⇒ 36 × 1000000 mm
In cm, h = 360000 cm