A) 1.9 mm
B) 1.7 mm
C) 1.5 mm
D) 1.3 mm
Correct Answer: B
Solution :
Given \[\frac{{{Y}_{A}}}{{{Y}_{B}}}=\frac{7}{4}\,\,\,\,\,\,\,\,\,\,{{L}_{A}}=2m\,\,\,\,\,\,\,\,\,\,{{A}_{A}}=\pi {{R}^{2}}\] \[{{L}_{B}}=1.5m\] \[{{A}_{B}}=\pi {{(2mm)}^{2}}\] \[\frac{F}{A}=Y\left( \frac{\ell }{L} \right)\] given F and \[\ell \]are same \[\Rightarrow \frac{AY}{L}\] is same \[\frac{{{A}_{A}}{{Y}_{A}}}{{{L}_{A}}}=\frac{{{A}_{B}}{{Y}_{B}}}{{{L}_{B}}}\] \[\Rightarrow \]\[\frac{\left( \pi {{R}^{2}} \right)\left( \frac{7}{4}{{Y}_{B}} \right)}{2}=\frac{\pi {{\left( 2mm \right)}^{2}}.{{Y}_{B}}}{1.5}\] \[R=1.74mm\]You need to login to perform this action.
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