AMU Medical AMU Solved Paper-2014

  • question_answer
    A thin non-conducting rod of length 50 cm has a positive charge of uniform linear density\[{{10}^{-12}}C/m\]. Find the electric potential due to the rod at a point, which is at a perpendicular distance of 1.0 cm from one-end of the rod\[({{\varepsilon }_{0}}=8.8\times {{10}^{-12}}F/m)\].

    A)  0.02 V                  

    B)  0.04 V

    C)  0.06 V                                  

    D) 1.02 V

    E) None of the above

    Correct Answer: E

    Solution :

    The given,     \[\lambda ={{10}^{-12}}C/m,\,l=50\,cm\], \[r=1\times {{10}^{-2}}m\] and        \[{{\varepsilon }_{0}}=8.8\times {{10}^{-12}}F/m\] We know that,                 \[\lambda =\frac{Q}{l}\]                 \[{{10}^{-12}}=\frac{Q}{50\,cm}\] or            \[{{10}^{-12}}=\frac{2Q}{2\times 50\,cm}\] \[{{10}^{-12}}=\frac{2Q}{100\,cm},{{10}^{-12}}=\frac{2Q}{1m},Q=\frac{1}{2}\times {{10}^{-12}}C\], Electric potential \[V=\frac{1}{4\pi {{\varepsilon }_{0}}}.\frac{Q}{r}\] \[=\frac{1}{4\times 3.14\times 8.8\times {{10}^{-12}}}.\frac{\frac{1}{2}\times {{10}^{-12}}}{1\times {{10}^{-2}}}\] \[=\frac{100}{221.05}=0.4\,V\]


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