J & K CET Medical J & K - CET Medical Solved Paper-2013

  • question_answer
    A parallel plate capacitor of capacitance 5 microfarad is charged to 120 V and then connected to another uncharged capacitor. If the potential falls to 40 V, and capacitance of the second capacitor is

    A)  5 microfarad      

    B)  10 microfarad

    C)  15 microfarad     

    D)  20 microfarad

    Correct Answer: C

    Solution :

     Change, \[Q=CV\] Given, \[C=5\mu F=5\times {{10}^{-6}}F,V=120\,V\] \[Q=5\times {{10}^{-6}}\times 120\] Also, \[5\times {{10}^{-6}}\times 120=40\times C\] \[\Rightarrow \] \[C=\frac{5\times {{10}^{-6}}\times 120}{40}=15\times {{10}^{-6}}F\] \[\Rightarrow \] \[C=15\mu F\]


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