VMMC VMMC Medical Solved Paper-2014

  • question_answer
    The length of a rod is 20 cm and area of cross-section 2\[c{{m}^{2}}\]. The Young's modulus of the material of wire is \[1.4\times {{10}^{11}}N{{m}^{-2}}\]. If the rod is compressed by 5 kg-wt along its length, then increase in the energy of the rod in joules will be

    A) \[8.57\times {{10}^{-6}}\]                            

    B) \[22.5\times {{10}^{-4}}\]

    C) \[9.8\times {{10}^{-5}}\]                              

    D) \[45.0\times {{10}^{-5}}\]

    Correct Answer: A

    Solution :

    Energy \[=\frac{1}{2}Fl\] \[=\frac{1}{2}\times F\times \left( \frac{FL}{AY} \right)\] \[=\frac{1}{2}\times \frac{{{F}^{2}}L}{AY}\] \[=\frac{1}{2}\times \frac{{{(50)}^{2}}\times 20\times {{10}^{-2}}}{2\times {{10}^{-4}}\times 1.4\times {{10}^{11}}}\] \[=8.57\times {{10}^{-6}}J\]


You need to login to perform this action.
You will be redirected in 3 sec spinner