Mechanical Properties of Solids - Result Question 2
2. The stress-strain curves are drawn for two different materials $X$ and $Y$. It is observed that the ultimate strength point and the fracture point are close to each other for material $X$ but are far apart for material $Y$.
We can say that materials $X$ and $Y$ are likely to be (respectively),
[NEET Odisha 2019]
(a) Plastic and ductile
(b) Ductile and brittle
(c) Brittle and ductile
(d) Brittle and plastic
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Solution:
- (c) Fracture point and ultimate strength point is close for material $X$, hence $X$ is brittle in nature and both points are far apart for material $Y$ hence it is ductile.
3
(a) Wire 1: $\overbrace{A, 3 \ell} F$
$ \begin{equation*} \Delta \ell=(\frac{F}{A Y}) 3 \ell \tag{i} \end{equation*} $
Wire 2:
$ \begin{equation*} \Delta \ell=(\frac{F^{\prime}}{3 A Y}) \ell \tag{ii} \end{equation*} $
From equation (i) & (ii),
$ \Delta \ell=(\frac{F}{A Y}) 3 \ell=(\frac{F^{\prime}}{3 A Y}) \ell \text{ or, } F^{\prime}=9 F $
