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Question
A cubic cm of gold is drawn into a wire 0.1 mm in diameter, find the length of the wire.
Solution
Let x be the length of wire.
Clearly, the volume of gold = volume of wire.
{Volume of gold = 1 cm3 = 1000 mm}
`1000 = pi ((0.1)/2)^2 xx x`
`22/7 xx 1/400 xx x = 1000`
`x = (1000 xx 400 xx 7)/22`
`= (1400 xx 1000)/11`
`= 127300 mm`
` x = 127.3m`
Hence, the length of wire is 127.3 m.
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