Part 1: A proton travels at a constant velocity, with directed along the +y directio...

Part 1: A proton travels at a constant velocity, with directed along the +y direction as shown in Figure 20.8A. At a particular moment, the proton is at the origin. Is the direction of the magnetic field at point A (a) along the +x direction, (b) along the -x direction, (c) along the +z direction, or (d) along the -z direction

Part 2: The proton is replaced by a long, straight wire carrying a current in the _y direction as shown in Figure 20.8B. Is the direction of the magnetic field at point A (a) along the +x direction, (b) along the -x direction, (c) along the +z direction, or (d) along the -z direction?