2. Solved Papers
  3. VIT Engineering

VIT Engineering VIT Engineering Solved Paper-2010

  • question_answer
    A small coil is introduced between the poles of an electromagnet so that its axis coincides with the magnetic field direction. The number of turns is n and the cross-sectional area of the coil is A. When the coil turns through \[180{}^\circ \] about its diameter, the charge flowing through the coil is Q. The total resistance of the circuit is R. What is the magnitude of the magnetic induction?

    A)  \[\frac{QR}{nA}\]             

    B)  \[\frac{2QR}{nA}\]

    C)  \[\frac{Qn}{2RA}\]          

    D)  \[\frac{QR}{2nA}\]

    Correct Answer: D

    Solution :

    Induced charge \[Q=-\frac{nBA}{R}(\cos \,{{\theta }_{2}}-\cos {{\theta }_{1}})\] \[=-\frac{nBA}{R}(\cos {{180}^{o}}-\cos {{0}^{o}})\] \[\Rightarrow \] \[B=\frac{QR}{2\pi A}\]  


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