Q. Two wires of the same material and length are stretched by the same force. Their masses are in the ratio 3:2. Their elongations are in the ratio
A) 3 : 2
B) 9 : 4
C) 2 : 3
D) 4 : 9
Explanation
(c) $Y = \frac{Fl}{A\mathrm{\Delta}l}\ or\ \mathrm{\Delta}l\ \propto \frac{1}{A}$
Again , $m = Alp,\ m\ \propto A$
$\therefore\ \mathrm{\Delta}l\ \propto \frac{1}{m}$
$\therefore\ \frac{\mathrm{\Delta}l_{1}}{\mathrm{\Delta}l_{2}} = \frac{m_{2}}{m_{1}} = \frac{2}{3}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.