Given,
Diameter of the copper wire = 1 cm
So, radius of the copper wire = 1/2 cm = 0.5 cm
Length of the copper rod = 8 cm
We know that,
Volume of the cylinder = π r2h
= π × 0.52× 8 ……. (i)
Length of the wire = 18 m = 1800 cm
Volume of the wire = π r2h
= π r2 × 1800 ….. (ii)
On equating both the equations, we have
π × 0.52× 8 = π r2 × 1800
r2 = 2 /1800 = 1/900
r = 1/30 cm
Therefore, the diameter of the wire is 1/15 cm i.e. 0.67 mm which is the thickness of the wire.
