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प्रश्न
A right circular cylindrical tunnel of diameter 2 m and length 40 m is to be constructed from a sheet of iron. The area of the iron sheet required in m2, is
पर्याय
40 \[\pi\]
80 \[\pi\]
160 \[\pi\]
200 \[\pi\]
उत्तर
Let r be the radius of the cylinder and h be its height.
It is given that:
`2r = 2 ⇒ r = 1 m`
And,
h = 40 m
Therefore, total surface area S of the sheet required is:
`S = 2 pirh`
`⇒ S = 2pi xx 1xx40`
`⇒ S = 80pi m^2`
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