JEE Mains · Physics · STD 11- 8. mechanical properties of solids
A uniform wire of length \(l\) of weight \(w\) is suspended from the roof with a weight of \(W\) at the other end. The stress in the wire at \(\dfrac{l}{3}\) distance from the top is \(\left(\dfrac{W}{A} + \dfrac{2}{\gamma}\dfrac{w}{A}\right)\), where, \(A\) is the cross sectional area of the wire. The value of \(\gamma\) is _______.
- A 6
- B 9
- C 12
- D 3
Answer & Solution
Correct Answer
(D) 3
Step-by-step Solution
Detailed explanation
Let \(T\) be the tension in the wire at a distance \(\dfrac{l}{3}\) from the top. The length of the wire below this point is \(l - \dfrac{l}{3} = \dfrac{2l}{3}\). The weight of this lower part of the wire is \(\dfrac{w}{l} \times \dfrac{2l}{3} = \dfrac{2w}{3}\). The total…
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