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The axle of a pulley of mass 1 kg is att...

The axle of a pulley of mass `1 kg` is attached to the end of an elastic string of length `1m`, cross- sectional area `10^(-3) m^(2)` and young's modulus `2xx10^(5) Nm^(-2) `,whose other end is fixed to the ceiling. A rope of negligible mass is placed on the pulley such that its left end is fixed to the ground and its right end is hanging freely , from the pulley which is at rest in equilibrium . Now, the rope and the pulley can be neglected. (Given, `g = 10 ms^(-2)`)

The elongation of the string before applying force is

A

`50 cm`

B

`5 cm`

C

`0.5 cm `

D

`0.05 cm `

Text Solution

Verified by Experts

The correct Answer is:
B
Initially , `DeltaL = (FL)/(AY)`
`= (10xx1)/10^(-3)xx2xx10^(5)`
`= 0.05 m = 5 cm `
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Knowledge Check

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