Q. Which of the following rods of same material undergoes maximum elongation when subjected to a given force?
A) L= 1m, d = 2 mm
B) L= 1m, d = 1 mm
C) L= 2m, d = 1 mm
D) L= 2m, d = 2 mm
Explanation
(c) As $l = \frac{F}{\pi\left( \frac{d^{2}}{4} \right)} \times \frac{L}{Y}\ so,\ l \propto \frac{L}{d^{2}}$
$\frac{L}{d^{2\ }}\ is\ maximum\ for\ option\ (c).\ $
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.