JEE Main & Advanced Sample Paper JEE Main - Mock Test - 26

  • question_answer
    The density p of water of bulk modulus B at a depth y in the ocean is related to the density at surface \[{{\rho }_{0}}\] by the relation

    A) \[\rho ={{\rho }_{0}}\left[ 1-\frac{{{\rho }_{0}}gy}{B} \right]\]

    B)        \[\rho ={{\rho }_{0}}\left[ 1+\frac{{{\rho }_{0}}gy}{B} \right]\]

    C) \[\rho ={{\rho }_{0}}\left[ 1+\frac{B}{{{\rho }_{0}}hgy} \right]\]

    D) \[\rho ={{\rho }_{0}}\left[ 1-\frac{B}{{{\rho }_{0}}hgy} \right]\]

    Correct Answer: B

    Solution :

    Bulk modulus, \[B=-{{V}_{0}}\frac{\Delta p}{\Delta V}\,\,\Rightarrow \,\Delta V=-{{V}_{0}}\frac{\Delta p}{B}\] \[\Rightarrow \,\,\,\,V={{V}_{0}}\left[ 1-\frac{\Delta p}{B} \right]\] \[\therefore \,\,\,\,Density,\,\,\,\rho ={{\rho }_{0}}\,{{\left[ 1-\frac{\Delta p}{B} \right]}^{-1}}\,\,=\,\,{{\rho }_{0}}\left[ 1+\frac{\Delta p}{B} \right]\] where,   \[\Delta p=p\,-{{p}_{0}}=\,\,h{{\rho }_{0}}g\] = pressure difference between depth and surface of ocean \[\therefore \,\,\,\,\,\rho ={{\rho }_{0}}\left[ 1+\frac{{{\rho }_{0}}gy}{B} \right]\,\,\,\,\,(As\,\,h=y)\]


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