Question

66 cubic centimetres of silver is drawn into a wire 1 mm in diameter. The length of the wire in metres will be:

• A. 84
• B. 90
• C. 168
• D. 336
• E. 420

Answer 1

The correct option is A

84

Let the length of the wire be `h'. Radius = $\frac{1}{2}$ mm =$\frac{1}{20}$cm. Then, $\frac{22}{7}\times \frac{1}{20}\times \frac{1}{20}\times h=66\iff h=\left(\frac{66\times 20\times 20\times 7}{22}\right)=8400cm=84m$