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प्रश्न
2.2 Cubic dm of grass is to be drawn into a cylinder wire 0.25cm in diameter. Find the length of wire?
उत्तर
Given that 2.2dm3 of grass is to be drawn into a cylindrical wire 0.25cmin diameter
Given diameter of cylindrical wire =0.25cm
radius of wire (r) =`d/2=(0.25)/2=0.125cm`
=`0.125xx10^-2m`
We have to find length of wire?
Let length of wire be ‘h’ (∵`1cm=10^-2m`)
Volume of Cylinder `=pir^2h`
Volume of brass of 2.2dm3 is equal to volume of cylindrical wire
`22/7(0.125xx10^-2)h=2.2xx10^-3`
⇒ `h=(2.2xx10^-3xx7)/(22(0.125xx10^-2)^2)`
⇒ `h=448m`
∴Length of cylindrical wire=448m
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