Along, straight wire lies along the l-axis and carries a 4.00-A current in the +z-direction. Find the

Question:

Along, straight wire lies along the l-axis and carries a 4.00-A current in the +z-direction. Find the magnetic field (magnitude and direction) produced at the following points by a o.500-mm segment of the wire centered at the origin:
(a) x = 2.00 m, y = 0, l = 0;
(b) x = 0,y = 2.00m,l = 0;
(c) x = 2.00m,y = 2.00m, z = 0;
(d) x = 0, y = 0, z = 2.00 m.