NEET Sample Paper NEET Sample Test Paper-12

  • question_answer
    A wire is stretched by 0.01 m by a certain force F. Another wire of the same material whose diameter and length are double to the original wire is stretched by the same force. Then its elongation will be

    A)  0.005 m                      

    B)  0.01 m

    C)  0.02 m                        

    D)  0.002 m

    Correct Answer: A

    Solution :

     \[l=\frac{FL}{\pi {{r}^{2}}\gamma }\]\[\therefore \]       \[l\propto \frac{L}{{{r}^{2}}}\](Y and F are constants) \[\frac{{{l}_{2}}}{{{l}_{1}}}=\frac{{{L}_{2}}}{{{L}_{1}}}\times {{\left( \frac{{{r}_{1}}}{{{r}_{2}}} \right)}^{2}}=(2)\times {{\left( \frac{1}{2} \right)}^{2}}=\frac{1}{2}\] \[\Rightarrow \]\[{{l}_{2}}=\frac{{{l}_{1}}}{2}=\frac{0.01\,m}{2}=0.005\,m\]


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