A long straight wire along the z-axis carries a current I in the negative z direction. The magnetic field vector B at a point having coordinates (x,y) in the z=0 plane is
-
UP 0 DOWN 0 0 0
A long straight wire along the z-axis carries a current I in the negative z direction. The magnetic field vector B at a point having coordinates (x,y) in the z=0 plane is