JIPMER Jipmer Medical Solved Paper-1999

  • question_answer
    If the radius of earth is reduced by 1% without changing the mass, then change in the acceleration due to gravity will be:

    A)  2% decrease    

    B)  2% increase      

    C)         1% increase     

    D)         1% decrease

    Correct Answer: A

    Solution :

    Here:     \[{{R}_{1}}=R\]                                  (initial radius) \[{{R}_{2}}=R\,(1-0.01)\]               (final radius)                       \[=0.99R\] Acceleration due to g \[g=\frac{GM}{{{R}^{2}}}\propto \frac{1}{{{R}^{2}}}\] Hence,  \[\frac{{{g}_{1}}}{{{g}_{2}}}={{\left( \frac{{{R}_{2}}}{{{R}_{1}}} \right)}^{2}}={{\left( \frac{0.99R}{R} \right)}^{2}}=0.98\] or,          \[{{g}_{2}}=\frac{{{g}_{1}}}{0.98}=1.02{{g}_{1}}\] Hence change in gravitational acceleration \[={{g}_{2}}-{{g}_{1}}=1.02{{g}_{1}}-{{g}_{1}}=0.02{{g}_{1}}=2%\]positive sign indicates increment.


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