A rod of 2 cm diameter and 30 cm length is converted into a wire of 3 cm length of uniform thickness. The diameter of the wire is?
Correct Answer: 2/√10 cm
Explanation:
Given, r1 = 1 cm, h1 = 30 cm, h2 = 300 cm.
Volume of rod = Volume of wire
⇒ πr12h1 = πr22h2
⇒ π x (1)2 x 30 = π x r22 x 300
⇒ r22 = 30/300
∴ r2 = 1/√10 cm
∴ diameter = 2r2
= 2 x 1/√10 = 2/√10cm.
