**Solution:** For copper wire: Diameter = 3 mm = 0.3 cm

For cylinder; length h = 12 cm, d = 10 cm

Density of copper = 8.88 gm cm3

Curved surface area of cylinder can be calculated as follows:

Length of wire can be calculated as follows:

Now, volume of wire can be calculated as follows:

Mass can be calculated as follows:

Mass = Density × Volume

= 8.88 × 88.7364

**= 788 g (approx)**