A long straight cylindrical region of radius a curries a current along its length. The current densi
Channel: Doubtnut
Date: 2021-11-02

A long straight cylindrical region of radius a curries a current along its length. The current density (J) varies from the axis to the edge of the cylindrical region according to `J = J_(0)  ( 1 –   r / a)`  Where r is distance from the axis `(0 lt r lta)`  (a)  Find the mean current density  (b)  Plot the variation of magnetic field (B) with distance r from the axis of the cylinder for `0 lt r lt a`.