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A wire of radius 0.2 mm is extended by 0.5% of its length...

A wire of radius 0.2 mm is extended by 0.5% of its length when supported by a load of 1.5 kg. Determine the Young's modulus for the material of the wire.

[Take g = 10 ms2]

A.

2.4×1010(Nm2)

B.

1.5×1010(Nm2)

C.

2.4×109(Nm2)

D.

1.3×1010(Nm2)

Correct answer is A

r=0.2mm = 2×104 e= 0.05% of L,=0.005L, m=1.5kgg=10ms2 ,  y=?,    

(1000 mm = 1m)

Y = FLAe

w = mg = 1.5 × 10 = 15

A = πr2 = 227×(2×104)2 = 1.26×107(m2)

⇒ Y = 15L1.26×107×0.005L

⇒ Y = 151.26×107×0.005

⇒ Y = 156.29×1010

Y = 2.4×1010(Nm2)