Question:
A copper wire of length $1.0 \mathrm{~m}$ and a steel wire of length $0.5 \mathrm{~m}$ having equal cross-sectional areas are joined end to end. The composite wire is stretched by a certain load which stretches the copper wire by $1 \mathrm{~mm}$. If the Young’s modulii of copper and steel are respectively $1.0 \times 10^{11} \mathrm{Nm}^{-}$ ${ }^{2}$ and $2.0 \times 10^{11} \mathrm{Nm}^{-2}$, the total extension of the composite wire is:
$1.75 \mathrm{~mm}$
$2.0 \mathrm{~mm}$
$1.50 \mathrm{~mm}$
$1.25 \mathrm{~mm}$
Question of from chapter.
JEE Main Previous Year April 23, 2013
Correct Option: 4
Solution:
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