2. Questions Bank
  3. 12th Class
  4. Physics
  5. Magnetism

12th Class Physics Magnetism Question Bank MCQ - Moving Charges and Magnetism

  • question_answer
    An element of \[0.05\text{ }\widehat{i}\text{ }m\]is placed at the origin as shown in figure which carries a large current of 10A. The magnetic field at a distance of 1 m in perpendicular direction is:

    A) \[4.5\times {{10}^{-8}}T\]                   

    B) \[5.5\times {{10}^{-8}}T\]

    C) \[5.0\times {{10}^{-8}}T\]                   

    D) \[7.5\times {{10}^{-8}}T\]

    Correct Answer: C

    Solution :

    (c) \[5.0\times {{10}^{-8}}T\]                         \[dB=\frac{{{\mu }_{0}}}{4\pi }\frac{Idl\,\sin \theta }{{{r}^{2}}}\] Here,     \[dl=\Delta x=0.05\,m,l=10\,A,\,r=1m\]             \[\sin \theta =\sin 90{}^\circ =1\] \[\therefore dB={{10}^{-7}}\times \frac{10\times 0.05\times 1}{{{(1)}^{2}}}\]             \[=0.50\times {{10}^{-7}}=5.0\times {{10}^{-8}}T\]


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