Question

A wire is stretched by X mm when a load of F is hanged on it. If the same wire goes over a pulley and two weight F each are hung at the two end's the what will be the elongation in the world



(a) X

(b) 2X

(c) X/2

(d) 0​

Answer 1

Answer:

(c) X/2 is the answer because the F divides the wire in half part

Answer 2

The right answer is:

Explanation:

The correct option is A) X

Referring to the hook's law

Modules of elasticity ,

E= A/W × 1/l

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here, l= original length of the wire

A= is the cross-sectional area of the wire

∴Elongation,

Δl= E/Wl

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Tension is W on both sides of the wire, and length is 1/2

​

Δl= AE/2/Wl = 2AE/Wl = 1/2

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∴ elongation of wire in totality is:

1/2 +1/2 = 1

Hence,

option (A) is the correct answer.