Q155 / 155 · WBJEE 2022 · Physics
Two wires $A$ and $B$ of same length are made of same material. Load $(F)$ vs. elongation $(x)$ graph for these two wires is shown in the figure. Then which of the following statement(s) is / are true?
Two wires $A$ and $B$ of same length are made of same material. Load $(F)$ vs. elongation $(x)$ graph for these two wires is shown in the figure. Then which of the following statement(s) is / are true?
- Correct answerAThe cross-section area of $A$ is greater than that of $B$.
- BYoung's modulus of $A$ is greater than Young's modulus of $B$.
- CThe cross-sectional area of $B$ is greater than that of $A$.
- Correct answerDYoung's modulus of both A and B are same.
Solution
same material have identical Young's Modulus.
For a given strain and Young's Modulus.
stress in same
$$
\begin{aligned}
&\frac{F_A}{A_A}=\frac{F_B}{A_B} \Rightarrow \frac{F_A}{F_B}=\frac{A_A}{A_B} \\
&\text { as } F_A>F_B, A_A>A_B
\end{aligned}
$$
Hence, the correct answer is options: 'A', 'D'.