Q. A fixed volume of iron is drawn into a wire of length $L$. The extension $x$ produced in this wire by a constant force $F$ is proportional to
A) $\frac{1}{L^{2}}$
B) $\frac{1}{L}$
C) $L^{2}$
D) $L$
Explanation
(c) $l = \frac{FL}{AY} = \frac{FL^{2}}{(AL)Y} = \frac{FL^{2}}{VY}$
If volume is fixed then $l \propto L^{2}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.