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

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

  • question_answer
                         A long solenoid has magnetic field strength of \[3.14\times {{10}^{-2}}T\] inside it when a current of 5A passes through it The number of turns in 1m Length of the solenoid is:        

    A) 1000                

    B) 3000  

    C) 10000                          

    D) 5000        

    Correct Answer: D

    Solution :

    (d) 5000.                                        We know that, \[B={{\mu }_{0}}nl\] \[\Rightarrow n\frac{B}{{{\mu }_{0}}l}=\frac{3.14\times {{10}^{-2}}}{4\pi \times {{10}^{-7}}\times 5}\]\[=\frac{3.14\times {{10}^{-2}}\times {{10}^{7}}}{4\times 3.14\times 5}=\frac{{{10}^{5}}}{20}=5000\]


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