The radius of a metallic sphere is 3 cm.it is melted and drawn into a wire of uniform circular section of 0.1 cm. the length of the wire will be (in m):
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 36
As we know when melting and changing the shape of substance, volume remains same
Volume of sphere = (4/3) × π × r3
Volume of cylinder = π × r2 × h
Hence, Volume of sphere = (4/3) × π × 33 = 36π and,
36π = π × (0.1)2 × h, h = 3600 cm or 36 m