Question

A metallic solid of volume $3,600m{m}^3$ melted and drawn into the form of a wire of height $12$ mm. Find the radius of the wire. (Use $\pi =3$)

• A. $12$ mm
• B. $11$ mm
• C. $10$ mm
• D. $14$ mm

Answer 1

The correct option is C $10$ mm

Let the wire is of the shape of the right circular cylinder.
Therefore, volume of the cylinder $=\pi r^{2}h$
3,600 = $3\times r^2\times 12$
$r^2=\frac{3,600}{3\times 12}$
$r^2=100$
Squaring on both the sides, we get
$r=10$ mm