Magnetic Field and Current Flow: Explained

[bodensee9]

Homework Statement

Hello: I have the following:
The component of the magnetic field parallel to a plane of sheet is the same magnitude on both sides, but changed direction by \frac{1}{2}\pi in going through the sheet.

I am supposed to explain what is going on. So B were to change direction, does that mean that the current is flowing along the z axis? (because B is always perpendicular to the direction of I)?

Thanks.

 

[kuruman]

Assume the sheet is in the plane of your computer screen. What is the direction of the z-axis relative to this plane?

 

[bodensee9]

if the sheet were the computer screen, then z would be into the page if the current were flowing to the left. I was thinking if the sheet were along the y-z plane, and the current were flowing along the y direction, then z would be pointing upwards. Does this mean that we have another field nearby that is changing its direction as it goes through the sheet? Thanks.