2. Solved Papers
  3. JEE Main & Advanced

JEE Main & Advanced JEE Main Solved Paper-2014

  • question_answer
    The coercivity of a small magnet where the Ferro magnet gets demagnetized is \[3\times {{10}^{3}}A\,{{m}^{-1}}.\]The currentrequired to be passed in a solenoid of length 10 cm and number of turns 100, so that the magnet getsdemagnetized when inside the solenoid, is :   JEE Main  Solved  Paper-2014

    A) 3 A                                         

    B) 6 A

    C) 30 mA                  

    D) 60 mA

    Correct Answer: A

    Solution :

    \[B={{\mu }_{0}}H\]                        \[{{\mu }_{0}}ni={{\mu }_{0}}H\] \[i=\frac{H}{n}=\frac{3\times {{10}^{3}}}{1000}=3A\]


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