AFMC AFMC Solved Paper-2008

  • question_answer
    A solenoid 1.5m long and 0.4 cm in diameter possesses 10 rums per cm length. A current of 5 A falls through it. The magnetic field at the axis inside the solenoid is

    A) \[2\times {{10}^{-3}}T\]                               

    B) \[271\times {{10}^{-5}}T\]

    C) \[4\times {{10}^{-2}}T\]                               

    D) \[4~\times {{10}^{-3}}T\]

    Correct Answer: A

    Solution :

    Magnetic field at the axis inside the solenoid \[B={{\mu }_{0}}ni\] Here, n = 10 turns/cm = 1000 turns/m, i = 5A \[\therefore \]    \[B=4\pi \times {{10}^{-7}}\times 1000\times 5\] \[=2\pi \times {{10}^{-3}}T.\]


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