The current density at a point is →J=(2×104^j) Am−2. Find the rate of charge flow through a cross-sectional area →S=(2^i+3^j) cm2.
|Why this question ?
For a finite area,
The direction of the current density is the same as the direction of the current. Thus, it is along the motion of the moving charges.
If a current I is uniformly distributed over an area, then