Question

A sphere having a radius of 3 cm is melted and elongated into a wire having a circular cross-section of radius 0.1 cm. Find the length of the wire?

(a) 2400 cm

(b) 3100 cm

(c) 1200 cm

(d) 3600 cm

I have been asked this question during a job interview.

My question comes from Conversion of Solid from One Shape to Another in section Surface Area and Volumes of Mathematics – Class 10

Answer 1

Correct choice is (d) 3600 cm

The explanation is: Volume of the wire = volume of the sphere

πr^2h = \(\frac {4}{3}\)πr^3

3.14 × 0.1^2 × h = \(\frac {4}{3}\) × 3.14 × 27

h = 3600 cm