Question

The diameter of a sphere is 6 cm. It is melted and drawn into a wire of diameter 2 mm. The length of the wire is

• A. 12 m
• B. 18 m
• C. 36 m
• D. 66 m

Answer 1

Answer: (C)

36 m

For cylindrical wire,

$d=0.2cm,r\frac{0.2}{2}=0.1cm$

Let the length of wire be $xcm$

So, according to problem Volume of cylindrical wire Volume of sphere

$=\pi r^{2}h=\frac{4}{3}\pi r^3$

$=0.1\times 0.1\times x=\frac{4}{3}\times 3\times 3\times 3$

$x=\frac{4\times 3\times 3\times 3}{0.1\times 0.1\times 0.1}$

$x=3600cm$ or $36cm$