Question

A copper rod of diameter 2 cm and length 10 cm is drawn into a wire of uniform thickness and length 10 m. Find the thickness of the wire.

Answer 1

Recall MU: 1m = 1000 mm and 1 cm = 10 mm

Diameter of the copper Rod = 2 cm

Radius of the copper rod = r= 1 cm

Length of the Rod = h = 10 cm

Length of the wire = h = 10 m = 1000 cm

Let suppose the radius of the wire = R

From the statement: Volume of the rod = volume of the wire

πr²h = πR²H

1 × 1 × 10 = 1000 × R

or R = 1/10 cm or 01. cm

Diameter of the wire = 2r = 2 × 0.1 = 0.2 cm

Therefore, the thickness of the wire is 0.2 cm or 2mm.