2. Questions Bank
  3. 12th Class
  4. Physics
  5. Electro Magnetic Induction

12th Class Physics Electro Magnetic Induction Question Bank MCQ - Electromagnetic Induction

  • question_answer
    A coil having an area \[{{A}_{0}}\] is placed in a magnetic field which changes from \[{{B}_{0}}\] to \[4{{\underline{B}}_{0}}\] in a time interval t. the e.m.f. induced in the coil will be:

    A) \[\frac{3{{A}_{0}}{{B}_{0}}}{t}\]                   

    B) \[\frac{4{{A}_{0}}{{B}_{0}}}{t}\]

    C) \[\frac{3{{B}_{0}}}{{{A}_{0}}t}\]                               

    D) \[\frac{4{{B}_{0}}}{{{A}_{0}}t}\]

    Correct Answer: A

    Solution :

    (a) \[\frac{3{{A}_{0}}{{B}_{0}}}{t}\] Emf induced, \[\varepsilon =\frac{d\phi }{dt}\]             \[=\frac{d}{dt}(BA)={{A}_{0}}\frac{dB}{dt}\]             \[={{A}_{0}}\left( \frac{4{{B}_{0}}-{{B}_{0}}}{t} \right)=\frac{3{{A}_{0}}{{B}_{0}}}{t}\]


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