A long, straight wire lies along the $z$ -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 $0.500 \mathrm{~mm}$ segment of the wire centered at the origin:
(a) $x=2.00 \mathrm{~m}, y=0, z=0$
(b) $x=0, y=2.00 \mathrm{~m}, z=0$
(c) $x=2.00 \mathrm{~m}, y=2.00 \mathrm{~m}, z=0$
(d) $x=0, y=0, z=2.00 \mathrm{~m}$