An iron rod with diameter 4 cm and length 12 cm is drawn into a wire of length 12 m of uniform thickness. Determine the thickness of the wire.
Answer & explanation
Correct answer: option 4
We have,
Length of the rod (h) = 12 cm
Diameter of the rod = 4 cm
then the radius (R) = 2 cm
Length of the wire (H) = 12 m
According to question,
Volume of rod = Volume of wire
=π(R)²H = πr²h
=r² = (2)² × \(\frac{12}{1200}\)
=r² = 0.04
= r = \(\sqrt {0.04}\) = 0.2
Thickness= diameter= 2 × 0.2 = 0.4 cm