CBSE Class 10 Answered

Radius of cylinder = 10/2 = 5 cm

CSA of cylinder = 2πRL = 2x3.14x5x12 = 376.8 cm²

Area covered in one turn of the given copper wire, 2πRD , where D is the diameter of the copper wire.

Hence number of turns of copper wire = CSA of cylinder/Area covered in one turn

= 2πRL/2πRD = L/D = 120 mm/3mm = 40 turns.

Total length of the wire = 2πRx number of turns = 2x3.14x5x40 = 1256 cm

Total mass of the wire = DensityxVolume

= Densityx π r² x Length of wire                ........r - radius of copper wire, 3/2 = 1.5 mm = 0.15 cm

= 8.88 x 3.14 x 0.15 x 0.15 x 1256 = 787.98 gm

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Team,

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