Mathematics
As shown in the adjoining figure, a wire of uniform thickness is rolled on a cylinder to cover it completely, without any overlapping. If the diameter of the wire is 0.25 cm, find :
(i) the number of turns made by the wire to cover the cylinder completely.
(ii) length of wire used.
Mensuration
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Answer
(i) Given,
Diameter of wire = 0.25 cm
No. of turns made by the wire to cover it completely
Hence, no. of turns made by the wire to cover it completely = 112.
(ii) On surrounding the circle, length of wire used
= 2πr
=
= 44 cm.
On turning 112 times, length of wire = 44 × 112 = 4928 cm = = 49.28 m.
Hence, length of wire used = 49.28 m.
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