The current density across a cylindrical conductor of radius R varies in magnitude according
Channel: Doubtnut
Date: 26/07/2020

The current density across a cylindrical conductor of radius R varies in magnitude according to the equation `J = J_0(1 - (r )/(R ))`  where r is the distance from the central  axis. Thus, the current density is a maximum `J_0` at that axis (r = 0) and decreases linearly to zero at the surface (r = R). Calculate the current in terms of `J_0` and the conductor 's cross - sectional area `A = piR^2`.