If 3.96 cubic dm of lead is to be drawn in to a cylindrical wire of diameter 0.6 cm, then the length of the wire (in metres), is:
Answer & explanation
Correct answer: option 3
Diameter of cylindrical wire = .6cm
We know that,
Volume of cylinder = πR2H
We also know that,
1 dm = 10 cm
1 dm3 = 1000 cm3
So, 3.96 dm3 = 3960 cm3
According to the formula,
3960 = \(\frac{22}{7}\)× (\(\frac{0.6}{2}\))2 × l
= l = 14000 cm
= 1m = 100cm
= 14000 cm = 140 m