Question

The load versus elongation graph for four wires of the same materials is shown in the figure The thinnest wire is represented by the line

• A. OC
• B. OD
• C. OA
• D. OB

Answer 1

The correct option is C OA

Young's modulus,

$Y=\frac{F.l}{A.△l}$

$F=\frac{YA}{l}△l$

Comparing this equation with $Y=mx$

$m=\frac{YA}{l}=$slope of $F-△l$ graph

$y$ and $l$ are fixed.

$\therefore m\propto A$

From this above relation we can say that, slope of the load-elongation graph will be less if the wire is thin.

$\therefore OA$ wire will be the thinnest.