Question

A wire elongates by l mm when a load W is hanged from it. If the wire goes over a pulley and two weights W each are hung at the two ends, the elongation of the wire will be (in mm)
A. (a) l
B. (b) 2l
C. (c) zero
D. (d) `l/2`

Answer 1

Correct Answer - A
Case (i)
At equilibrium, `T=W`
`Y=(W//A)/(l//L)` …(1)
Case (ii) At equilibrium `T=W`
`:. Y=(W//A)/(l//2)impliesY=(W//A)/(l//L)`
`implies` Elongation is the same.