Q 11-08-005NEETJEE MainMedium
Two wires P and Q are made of the same material. The length of Q is twice that of P, and the diameter of P is twice that of Q. The same load is hung from each. The ratio of the extension of P to that of Q is
Answer: (B) $1 : 8$
$\Delta L = \dfrac{FL}{AY} \propto \dfrac{L}{d^2}$.
Take P: length $L$, diameter $2d$; Q: length $2L$, diameter $d$.
$\dfrac{\Delta L_P}{\Delta L_Q} = \dfrac{L/(4d^2)}{2L/d^2} = \dfrac{1}{8}$.
Solution by Sreeraj P, M.Sc Physics