Question

The radius of a sphere is 9 cm It is melted and drawn into a wire of diameter 2 mm Find the lenght of the wire in meters

• A. 972
• B. 792
• C. 292
• D. 97.2

Answer 1

Answer: (A)

972

The wire is cylindrical in shape So its volume will be $=\pi r^{2}h$ where h is the length of the wire here
Volume of the sphere = Volume of the wire
i.e. $=\pi {\left(0.1\right)}^{2}h=\frac{4}{3}\pi {\left(9\right)}^3$ (Since 1 mm = 0.1 cm)
or h=97200 cm = 972 m