Q. The stress versus strain graphs for wires of two materials $A$ and $B$ are as shown in the figure. If $Y_{A}$ and $Y_{B}$ are the Young’s modulii of the materials, then
A) $Y_{B} = 2Y_{A}$
B) $Y_{A} = Y_{B}$
C) $Y_{B} = 3Y_{A}$
D) $Y_{A} = 3Y_{B}$
Explanation
(d) $\frac{Y_{A}}{Y_{B}} = \frac{\tan\theta_{A}}{\tan\theta_{B}} = \frac{\tan 60}{\tan 30} = \frac{\sqrt{3}}{1/\sqrt{3}} = 3 \Rightarrow Y_{A} = 3Y_{B}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.