2. Sample Papers
  3. JEE Main & Advanced

JEE Main & Advanced Sample Paper JEE Main - Mock Test - 5

  • question_answer
    The instantaneous magnetic flux \[\phi \]in a circuit is \[\phi =4{{t}^{2}}-4t+1Wb\] The total resistance of the circuit is \[10\Omega \]. At \[t=\frac{1}{2}s,\]the induced current in the circuit is

    A) OA      

    B) 0.6 A

    C) 0.4 A   

    D) 0.2 A

    Correct Answer: A

    Solution :

    [a]: Here,\[\phi =4{{t}^{2}}-4t+1\] Induced current, \[|\varepsilon |=\frac{d\phi }{dt}\] \[=\frac{d}{dt}(4{{t}^{2}}-4t+1)=8t-4\] Induced current, \[I=\frac{|\varepsilon |}{R}=\frac{8t-4}{10}\] At \[t=\frac{1}{2}s,I=\frac{8\times \frac{1}{2}-4}{10}=0A\]


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